How to Set Up a VLAN

Diego Asturias UPDATED: July 11, 2023

If you want to improve your network security and performance, learning how to set up a VLAN properly is all you need. Virtual LANs are powerful networking tools that allow you to segment your network into logical groups and isolate traffic between them.

In this post, we will go through the steps required to set up a VLAN in your network. We will configure two switches along with their interfaces and VLANs, respectively.

So, let’s dive in and learn how to set up VLANs and take your network to the next level.

Table of Contents

  • What is a VLAN?
  • Preparing for VLAN configuration
    • Our Lab
    • Network Diagram
  • How to set up a VLAN on a Switch?
    • Let’s connect to the Switch
    • Configure VLANs
    • Assign switch ports to VLANs
    • Configure trunk ports
  • Extra Configuration to Consider

What is a VLAN?

Before we go deep into learning how to set up a VLAN and provide examples, let’s understand the foundations of VLANs (or Virtual Local Area Networks).

In a nutshell, VLANs are logical groupings of devices that rely on Layer 2 addresses (MAC) for communication. VLANs are implemented to segment a physical network (or large Layer two broadcast domains) into multiple smaller logical networks (isolated broadcast domains).

Each VLAN behaves as a separate network with its own broadcast domain. VLANs help prevent broadcast storms (extreme amounts of broadcast traffic). They also help control traffic and overall improve network security and performance.

Preparing for VLAN configuration

Although VLANs are usually left for Layer 2 switches, in reality, any device (including routers and L3 switches) with switching capabilities and support of VLAN configuration should be an excellent fit for VLANs. In addition, VLANs are supported by different vendors, and since each vendor has a different OS and code, the way the VLANs are configured may slightly change.

Furthermore, you can also use specific software such as network diagramming and simulation to help you create network diagrams and test your configuration.

Our Lab

We will configure a popular Cisco (IOS-based) switch for demonstration purposes. We will use Boson NetSim (a network simulator for Cisco networking hardware and software) to run Cisco IOS simulated commands. This simulation is like you were configuring an actual Cisco switch or router.

Network Diagram

To further illustrate how to set up a VLAN, we will work on the following network diagram. We will configure two VLANs in two different switches. We will then configure each port on the switches connected to a PC. We will then proceed to configure the trunk port, which is vital for VLAN traffic.

Network Diagram

Network diagram details

  • S2 and S3 (Switch 2 and Switch 3) – Two Cisco L2 Switches connecting PCs at different VLANs (VLAN 10 and VLAN 20) via Fast Ethernet interfaces.
  • VLANs 10 and VLAN20. These VLANs configured in L2 switches (S2 and S3) create a logical grouping of PCs within the network. In addition, each VLAN gets a name, VLAN 10 (Engineering) and VLAN 20 (Sales).
  • PCs. PC1, PC2, PC3, and PC4 are each connected to a specific L2 switch.

How to set up a VLAN on a Switch?

So now that you know the VLAN configuration we will be using, including the number of switches, VLAN ID, VLAN name, and the devices or ports that will be part of the configuration, let’s start setting up the VLANs.

Note: VLAN configuration is just a piece of the puzzle. Switches also need proper interface configuration, authentication, access, etc. To learn how to correctly connect and configure everything else, follow the step-by-step guide on how to configure a Cisco Switch. 

a. Let’s connect to the switch

Inspect your hardware and find the console port. This port is usually located on the back of your Cisco switch. You can connect to the switch’s “console port” using a console cable (or rollover). Connect one end of the console cable to the switch’s console port and the other to your computer’s serial port.

Note: Obviously, not all modern computers have serial ports. Some modern switches come with a Mini USB port or AUX port to help with this. But if your hardware doesn’t have these ports, you can also connect to the switch port using special cables like an RJ-45 rollover cable, a Serial DB9-to-RJ-45 console cable, or a serial-to-USB adapter. 

  • Depending on your switch’s model, you can configure it via Command Line Interface (CLI) or Graphical User Interface (GUI). We will connect to the most popular user interface: The IOS-based CLI. 
  • To connect to your switch’s IOS-based CLI, you must use a terminal emulator on your computer, such as PuTTY or SecureCRT.
  • You’ll need to configure the terminal emulator to use the correct serial port and set the baud rate to 9600. Learn how to properly set these parameters in the Cisco switching configuration guide.
  • In the terminal emulator, press Enter to activate the console session. The Cisco switch should display a prompt asking for a username and password.
  • Enter your username and password to log in to the switch.
connect to the switch

b. Configure VLANs

According to our previously shown network diagram, we will need two VLANs; VLAN 10 and VLAN 20.

  • To configure Layer 2 switches, you need to enter the privileged EXEC mode by typing “enable” and entering the password (if necessary).
  • Enter the configuration mode by typing “configure terminal.”
  • Create the VLAN with “vlan <vlan ID>” (e.g., “vlan 10”).
  • Name the VLAN by typing “name <vlan name>” (e.g., “name Sales”).
  • Repeat these two steps for each VLAN you want to create.

Configuration on Switch 2 (S2)

S2# configure terminal

S2(config)# vlan 10

S2(config-vlan)# name Engineering

S2(config-vlan)# end

S2# configure terminal

S2(config)# vlan 20

S2(config-vlan)# name Sales

S2(config-vlan)# end

Use the “show vlan” command to see the configured VLANs. From the output below, you’ll notice that the two new VLANs 10 (Engineering) and 20 (Sales) are indeed configured and active but not yet assigned to any port.

Configure VLANs

Configuration on Switch 3 (S3)

S3# configure terminal

S3(config)# vlan 10

S3(config-vlan)# name Engineering

S3(config-vlan)# end

S3# configure terminal

S3(config)# vlan 20

S3(config-vlan)# name Sales

S3(config-vlan)# end

Configuration on Switch 3 (S3)

Note: From the output above, you might have noticed VLAN 1 (default), which is currently active and is assigned to all the ports in the switch. This VLAN, also known as native VLAN, is the default VLAN on most Cisco switches. It is used for untagged traffic on a trunk port. This means that all traffic that is not explicitly tagged with VLAN information will be sent to this default VLAN. 

Now, let’s remove those VLAN 1 tags from interfaces Fa0/2 and Fa0/3. Or in simple words let’s assign the ports to our newly created VLANs.

c. Assign switch ports to VLANs

In the previous section, we created our VLANs; now, we must assign the appropriate switch ports to the correct VLANs. The proper steps to assign switch ports to VLANs are as follows:

  • Enter configuration mode. Remember to run these commands under the configuration mode (configure terminal).
  • Assign ports to the VLANs by typing “interface <interface ID>” (e.g., “interface GigabitEthernet0/1”).
  • Configure the port as an access port by typing “switchport mode access”
  • Assign the port to a VLAN by typing “switchport access vlan <vlan ID>” (e.g., “switchport access vlan 10”).
  • Repeat these steps for each port you want to assign to a VLAN.

Let’s refer to a section of our network diagram

network diagram

Configuration on Switch 2 (S2)

S2(config)# interface fastethernet 0/2

S2(config-if)# switchport mode access

S2(config-if)# switchport access vlan 10

S2(config)# interface fastethernet 0/3

S2(config-if)# switchport mode access

S2(config-if)# switchport access vlan 20

Configuration on Switch 2 (S2)

Use the “show running-configuration” to see the new configuration taking effect on the interfaces.

Configuration on Switch 3 (S3)

S3(config)# interface fastethernet 0/2

S3(config-if)# switchport mode access

S3(config-if)# switchport access vlan 10

S3(config)# interface fastethernet 0/3

S3(config-if)# switchport mode access

S3(config-if)# switchport access vlan 20

Configuration on Switch 3 (S3)

A “show running-configuration” can show you our configuration results.

show running-configuration

d. Configure trunk ports

Trunk ports are a type of switch port mode (just like access) that perform essential tasks like carrying traffic for multiple VLANs between switches, tagging VLAN traffic, supporting VLAN management, increasing bandwidth efficiency, and allowing inter-VLAN routing.

If we didn’t configure trunk ports between our switches, the PCs couldn’t talk to each other on different switches, even if they were on the same VLAN.

Here’s a step by step to configuring trunk ports

  • Configure a trunk port to carry traffic between VLANs by typing “interface <interface ID>” (e.g., “interface FastEthernet0/12”).
  • Set the trunk encapsulation method (dot1q). The IEEE 802.1Q (dot1q) trunk encapsulation method is the standard tagging Ethernet frames with VLAN information.
  • Configure the port as a trunk port by typing “switchport mode trunk”.
  • Repeat the steps for each trunk port you want to configure.

Note (on redundant trunk links): To keep our article simple, we will configure one trunk link. However, keep in mind that any good network design (including trunk links) would need redundancy. One trunk link between switches is not an optimal redundant solution for networks on production. To add redundancy, we recommend using EtherChannel to bundle physical links together and configure the logical link as a trunk port. You can also use Spanning Tree Protocol (STP) by using the “spanning-tree portfast trunk” command.

Let’s refer to our network diagram

network diagram

Configuration on Switch 2 (S2)

S2(config)# interface fastethernet 0/12

S2(config-if)# switchport trunk encapsulation dot1q

S2(config-if)# switchport mode trunk

S2(config-if)# exit

Configuration on Switch 2 (S2)

Configuration on Switch 3 (S3)

S3(config)# interface fastethernet 0/24

S3(config-if)# switchport trunk encapsulation dot1q

S3(config-if)# switchport mode trunk

S3(config-if)# exit

Configuration on Switch 3 (S3)

Note: You can use different types of trunk encapsulation such as dot1q and ISL, just make sure both ends match the type of encapsulation.

Extra Configuration to Consider

Once you finish with VLAN and trunk configuration, remember to test VLAN connectivity between PCs, you can do this by configuring the proper IP addressing and doing a simple ping. Below are other key configurations related to your new VLANs that you might want to consider.

a. Ensure all your interfaces are up and running

To ensure that your interfaces are not administratively down, issue a “no shutdown” (or ‘no shut’) command on all those newly configured interfaces. Additionally, you can also use the “show interfaces” to see the status of all the interfaces.

no shutdown command

b. (Optional) enable inter-VLAN

VLANs, as discussed earlier, separate broadcast domains (Layer 2) — they do not know how to route IP traffic because Layer 2 devices like switches can’t accept IP address configuration on their interfaces. To allow inter-VLAN communication (PCs on one VLAN communicate with PCs on another VLAN), you would need to use a Layer 3 device (a router or L3 switch) to route traffic.

There are three ways to implement inter-VLAN routing: an L3 router with multiple Ethernet interfaces, an L3 router with one router interface using subinterfaces (known as Router-On-a-Stick), and an L3 switch with SVI.

We will show a step-by-step on how to configure Router-On-a-Stick for inter-VLAN communications. 

  • Connect the router to one switch via a trunk port.
  • Configure subinterfaces on the router for each VLAN (10 and 20 in our example). To configure subinterfaces, use the “interface” command followed by the VLAN number with a period and a subinterface number (e.g., “interface FastEthernet0/0.10” for VLAN 10). For example, to configure subinterfaces for VLANs 10 and 20, you would use the following commands:

> router(config)# interface FastEthernet 0/0

> router(config-if)# no shutdown

> router(config-if)# interface FastEthernet 0/0.10

> router(config-subif)# encapsulation dot1Q 10

> router(config-subif)# ip address

> router(config-subif)# interface FastEthernet 0/0.20

> router(config-subif)# encapsulation dot1Q 20

> router(config-subif)# ip address

  • Configure a default route on the router using the “ip route” command. This is a default route to the Internet through a gateway at IP address For example:

> router(config)# ip route

c. Configure DHCP Server

To automatically assign IP addresses to devices inside the VLANs, you will need to configure a DHCP server. Follow these steps:

  1. The DHCP server should also be connected to the VLAN.
  2. Configure the DHCP server to provide IP addresses to devices in the VLAN.
  3. Configure the router to forward DHCP requests to the DHCP server by typing “ip helper-address <ip address>” (e.g., “ip helper-address”).

Final Words

By following the steps outlined in this post, you can easily set up a VLAN on your switch and effectively segment your network. Keep in mind to thoroughly test your VLAN configuration and consider additional configuration options to optimize your network for your specific needs.

With proper setup and configuration, VLANs can greatly enhance your network’s capabilities and 10x increase its performance and security.

Source :

The Best Network Monitoring Tools & Software

Marc Wilson UPDATED: October 20, 2023

The realm of Network Monitoring Tools, Software, and Vendors is Huge, to say the least. New software, tools, and utilities are being launched almost every year to compete in an ever-changing marketplace of IT monitoringserver monitoring, and system monitoring software.

I’ve test-driven, played with and implemented dozens during my career and this guide rounds up the best ones in an easy-to-read format and highlighted their main strengths and why I think they are in the top class of tools to use in your IT infrastructure and business.

Some of the features I am looking for are device discovery, uptime/downtime indicators, along with robust and thorough alerting systems (via email/SMS),  NetFlow and SNMP Integration as  well as considerations that are important with any software purchase such as ease of use and value for money.

The features from above were all major points of interest when evaluating software suites for this article and I’ll try to keep this article as updated as possible with new feature sets and improvements as they are released.

Here is our list of the top network monitoring tools:

  1. Auvik – EDITOR’S CHOICE This cloud platform provides modules for LAN monitoring, Wi-Fi monitoring, and SaaS system monitoring. The network monitoring package discovers all devices, maps the network, and then implements automated performance tracking. Get a 14-day free trial.
  2. Paessler PRTG Network Monitor – FREE TRIAL A collection of monitoring tools and many of those are network monitors. Runs on Windows Server. Start a 30-day free trial.
  3. SolarWinds Network Performance Monitor – FREE TRIAL The leading network monitoring system that uses SNMP to check on network device statuses. This monitoring tool includes autodiscovery that compiles an asset inventory and automatically draws up a network topology map. Runs on Windows Server. Start 30-day free trial.
  4. Checkmk – FREE TRIAL This hybrid IT infrastructure monitoring package includes a comprehensive network monitor that provides device status tracking and traffic analysis functions via the integration with ntop. Available as a Linux install package, Docker package, appliance and cloud application available in cloud marketplaces. Get a 30-day free trial.
  5. Datadog Network Monitoring – FREE TRIAL Provides good visibility over each of the components of your network and the connections between them – be it cloud, on-premises or hybrid environment. Troubleshoot infrastructure, apps and DNS issues effortlessly.
  6. ManageEngine OpManager – FREE TRIAL An SNMP-based network monitor that has great network topology layout options, all based on an autodiscovery process. Installs on Windows Server and Linux.
  7. NinjaOne RMM – FREE TRIAL This cloud-based system provides remote monitoring and management for managed service providers covering the systems of their clients.
  8. Site24x7 Network Monitoring – FREE TRIAL A cloud-based monitoring system for networks, servers, and applications. This tool monitors both physical and virtual resources.
  9. Atera – FREE TRIAL A cloud-based package of remote monitoring and management tools that include automated network monitoring and a network mapping utility.
  10. ManageEngine RMM Central – FREE TRIAL A powerful asset and network management that includes patching, remote access, and automated remediation.

Related Post: Best Bandwidth Monitoring Software and Tools for Network Traffic Usage

The Top Network Monitoring Tools and Software

Below you’ll find an updated list of the Latest Tools & Software to ensure your network is continuously tracked and monitored at all times of the day to ensure the highest up-times possible. Most of them have free Downloads or Trials to get you started for 15 to 30 days to ensure it meets your requirements.

What should you look for in network monitoring tools?

We reviewed the market for network monitoring software and analyzed the tools based on the following criteria:

  • An automated service that can perform network monitoring unattended
  • A device discovery routine that automatically creates an asset inventory
  • A network mapping service that shows live statuses of all devices
  • Alerts for when problems arise
  • The ability to communicate with network devices through SNMP
  • A free trial or a demo for a no-cost assessment
  • Value for money in a package that provides monitoring for all network devices at a reasonable price

With these selection criteria in mind, we have defined a shortlist of suitable network monitoring tools for all operating systems.

1. Auvik – FREE TRIAL

Auvik Network Monitoring

Auvik is a SaaS platform that offers a network discovery and mapping system that automates enrolment and then continues to operate in order to spot changes in network infrastructure. This system is able to centralize and unify the monitoring of multiple sites.

Key Features:

  • A SaaS package that includes processing power and storage space for system logs as well as the monitoring software
  • Centralizes the monitoring of networks on multiple sites
  • Watches over network device statuses
  • Offers two plans: Essential and Performance
  • Network traffic analysis included in the higher plan
  • Monitors virtual LANs as well as physical networks
  • Autodiscovery service
  • Network mapping
  • Alerts for automated monitoring
  • Integrations with third-party complimentary systems

Why do we recommend it?

Auvik is a cloud-based network monitoring system. It reaches into your network, identifies all connected devices, and then creates a map. While SolarWinds Network Performance Monitor also performs those tasks, Auvik is a much lighter tool that you don’t have to host yourself and you don’t need deep technical knowledge to watch over a network with this automated system.

Auvik’s network monitoring system is automated, thanks to its system of thresholds. The service includes out-of-the-box thresholds that are placed on most of the metrics that the network monitor tracks. It is also possible to create custom thresholds.

Once the monitoring service is operating, if any of the thresholds are crossed, the system raises an alert. This mechanism allows technicians to get on with other tasks, knowing that the thresholds give them time to avert system performance problems that would be noticeable to users.

Network management tools that are included in the Auvik package include configuration management to standardize the settings of network devices and prevent unauthorized changes.

The processing power for Auvik is provided by the service’s cloud servers. However, the system requires collectors to be installed on each monitored site. This software runs on Windows Server and Ubuntu Linux. It is also possible to run the collector on a VM. Wherever the collector is located, the system manager still accesses the service’s console, which is based on the Auvik server, through any standard Web browser.

Who is it recommended for?

Smaller businesses that don’t have a team to support IT would benefit from Auvik. It needs no software maintenance and the system provides automated alerts when issues arise, so your few IT staff can get on with supporting other resources while Auvik looks after the network.


  • A specialized network monitoring tool
  • Additional network management utilities
  • Configuration management included
  • A cloud-based service that is accessible from anywhere through any standard Web browser
  • Data collectors for Windows Server and Ubuntu Linux


  • The system isn’t expandable with any other Auvik modules

Auvik doesn’t publish its prices by you can access a 14-day free trial.


Auvik is our top pick for a network monitoring tool because it is a hosted SaaS package that provides all of your network monitoring needs without you needing to maintain the software. The Auvik platform installs an agent on your site and then sets itself up by scanning the network and identifying all devices. The inventory that this system generates gives you details of all of your equipment and provides a basis for network topology maps. Repeated checks on the network gather performance statistics and if any metric crosses a threshold, the tool will generate an alert.  You can centralize the monitoring of multiple sites with this service.

Download: Get a 14-day FREE Trial

Official Site:

OS: Cloud-based

2. PRTG Network Monitor from Paessler – FREE TRIAL

PRTG Network Monitor

PRTG Network Monitor software is commonly known for its advanced infrastructure management capabilities. All devices, systems, traffic, and applications in your network can be easily displayed in a hierarchical view that summarizes performance and alerts. PRTG monitors the entire IT infrastructure using technology such as SNMP, WMI, SSH, Flows/Packet Sniffing, HTTP requests, REST APIs, Pings, SQL, and a lot more.

Key Features:

  • Autodiscovery that creates and maintains a device inventory
  • Live network topology maps are available in a range of formats
  • Monitoring for wireless networks as well as LANs
  • Multi-site monitoring capabilities
  • SNMP sensors to gather device health information
  • Ping to check on device availability
  • Optional extra sensors to monitor servers and applications
  • System-wide status overviews and drill-down paths for individual device details
  • A protocol analyzer to identify high-traffic applications
  • A packet sniffer to collect packet headers for analysis
  • Color-coded graphs of live data in the system dashboard
  • Capacity planning support
  • Alerts on device problems, resource shortages, and performance issues
  • Notifications generated from alerts that can be sent out by email or SMS
  • Available for installation on Windows Server or as a hosted cloud service

Why do we recommend it?

Paessler PRTG Network Monitor is a very flexible package. Not only does it monitor networks, but it can also monitor endpoints and applications. The PRTG system will discover and map your network, creating a network inventory, which is the basis for automated monitoring. You put together your ideal monitoring system by choosing which sensors to turn on. You pay for an allowance of sensors.

It is one of the best choices for organizations with low experience in network monitoring software. The user interface is really powerful and very easy to use.

A very particular feature of PRTG is its ability to monitor devices in the data center with a mobile app. A QR code that corresponds to the sensor is printed out and attached to the physical hardware. The mobile app is used to scan the code and a summary of the device is displayed on the mobile screen.

In summary, Paessler PRTG is a flexible package of sensors that you can tailor to your own needs by deciding which monitors to activate. The SNMP-based network performance monitoring routines include an autodiscovery system that generates a network asset inventory and topology maps. You can also activate traffic monitoring features that can communicate with switches through NetFlow, sFlow, J-Flow, and IPFIX. QoS and NBAR features enable you to keep your time-sensitive applications working properly.

Who is it recommended for?

PRTG is available in a Free edition, which is limited to 100 sensors. This is probably enough to support a small network. Mid-sized and large organizations should be interested in paying for larger allowances of sensors. The tool can even monitor multiple sites from one location.


  • Uses a combination of packet sniffing, WMI, and SNMP to report network performance data
  • Fully customizable dashboard is great for both lone administrators as well as NOC teams
  • Drag and drop editor makes it easy to build custom views and reports
  • Supports a wide range of alert mediums such as SMS, email, and third-party integrations into platforms like Slack
  • Each sensor is specifically designed to monitor each application, for example, there are prebuilt sensors whose specific purpose is to capture and monitor VoIP activity
  • Supports a freeware version


  • Is a very comprehensive platform with many features and moving parts that require time to learn

PRTG has a very flexible pricing plan, to get an idea visit their official pricing webpage below. It is free to use for up to 50 sensors. Beyond that you get a 30-day free trial to figure out your network requirements.

Paessler PRTGDownload a 30-day FREE Trial

3. SolarWinds Network Performance Monitor – FREE TRIAL

SolarWinds Network Performance Monitor with Free Trial

SolarWinds Network Performance Monitor is easy to setup and can be ready in no time. The tool automatically discovers network devices and deploys within an hour. Its simple approach to oversee an entire network makes it one of the easiest to use and most intuitive user interfaces.

Key Features:

  • Automatically Network Discovery and Scanning for Wired and Wifi Computers and Devices
  • Support for Wide Array of OEM Vendors
  • Forecast and Capacity Planning
  • Quickly Pinpoint Issues with Network Performance with NetPath™ Critical Path visualization feature
  • Easy to Use Performance Dashboard to Analyze Critical Data points and paths across your network
  • Robust Alerting System with options for Simple/Complex Triggers
  • Monitor CISCO ASA networks with their New Network Insight™ for CISCO ASA
  • Monitor ACL‘s, VPN, Interface and Monitor on your Cisco ASA
  • Monitor Firewall rules through Firewall Rules Browser
  • Hop by Hop Analysis of Critical Network Paths and Components
  • Automatically Discover Networks and Map them along with Topology Views
  • Manage, Monitor and Analyze Wifi Networks within the Dashboard
  • Create HeatMaps of Wifi Networks to pin-point Wifi Dead Spots
  • Monitor Hardware Health of all Servers, Firewalls, Routers, Switches, Desktops, laptops and more
  • Real-Time Network and Netflow Monitoring for Critical Network Components and Devices

Why do we recommend it?

SolarWinds Network Performance Monitor is the leading network monitoring tool in the world and this is the system that the other monitor providers are chasing. Like many other network monitors, this system uses the Simple Network Management Protocol (SNMP) to gather reports on network devices. The strength of SolarWinds lies in the deep technical knowledge of its support advisors, which many other providers lack.

The product is highly customizable and the interface is easy to manage and change very quickly. You can customize the web-based performance dashboards, charts, and views. You can design a tailored topology for your entire network infrastructure. You can also create customized dependency-aware intelligent alerts and much more.

SolarWinds NPM Application Summary

The software is sold by separate modules based on what you use. SolarWinds Network Performance Monitor Price starts from $1,995 and is a one-time license including 1st-year maintenance.

SolarWinds NPM has an Extensive Feature list that make it One of the Best Choices for Network Monitoring Solutions

SolarWinds NPM is able to track the performance of networks autonomously through the use of SNMP procedures, producing alerts when problems arise. Alerts are generated if performance dips and also in response to emergency notifications sent out by device agents. This system means that technicians don’t have to watch the monitoring screen all the time because they know that they will be drawn back to fix problems by an email or SMS notification.

SolarWinds NPM - NetPath Screenshot
NetPath Screenshot

Who is it recommended for?

SolarWinds Network Performance Monitor is an extensive network monitoring system and it is probably over-engineered for use by a small business. Mid-sized and large companies would benefit from using this tool.


  • Supports auto-discovery that builds network topology maps and inventory lists in real-time based on devices that enter the network
  • Has some of the best alerting features that balance effectiveness with ease of use
  • Supports both SNMP monitoring as well as packet analysis, giving you more control over monitoring than similar tools
  • Uses drag and drop widgets to customize the look and feel of the dashboard
  • Tons of pre-configured templates, reports, and dashboard views


  • This is a feature-rich enterprise tool designed for sysadmin, non-technical users may some features overwhelming

You can start with a 30-day free trial.

SolarWinds NPMDownload a 30-day FREE Trial!

4. Checkmk – FREE TRIAL

Checkmk Uplink Bandwidth Graph

Checkmk is an IT asset monitoring package that has the ability to watch over networks, servers, services, and applications. The network monitoring facilities in this package provide both network device status tracking and network traffic monitoring.

Features of this package include:

  • Device discovery that cycles continuously, spotting new devices and removing retired equipment
  • Creation of a network inventory
  • Registration of switches, routers, firewalls, and other network devices
  • Creation of a network topology map
  • Continuous device status monitoring with SNMP
  • SNMP feature report focus for small businesses
  • Performance thresholds with alerts
  • Wireless network monitoring
  • Protocol analysis
  • Traffic throughput statistics per link
  • Switch port monitoring
  • Gateway transmission speed tracking
  • Network traffic data extracted with ntop
  • Can monitor a multi-vendor environment

Why do we recommend it?

The Checkmk combination of network device monitoring and traffic monitoring in one tool is rare. Most network monitoring service creators split those two functions so that you have to buy two separate packages. The Checkmk system also gives you application and server monitoring along with the network monitoring service.

The Checkmk system is easy to set up, thanks to its autodiscovery mechanism. This is based on SNMP. The program will act as an SNMP Manager, send out a broadcast requesting reports from device agents, and then compile the results into an inventory. The agent is the Checkmk package itself if you choose to install the Linux version or it is embedded on a device if you go for the hardware option. If you choose the Checkmk Cloud SaaS option, that platform will install an agent on one of your computers.

The SNMP Manager constantly re-polls for device reports and the values in these appear in the Checkmk device monitoring screen. The platform also updates its network inventory according to the data sent back by device agents in each request/response round. The dashboard also generates a network topology map from information in the inventory. So, that map updates whenever the inventory changes.

Checkmk Network Topology

While gathering information through SNMP, the tool also scans the headings of passing packets on the network to compile traffic statistics. Basically, the tool provides a packet count which enables it to quickly calculate a traffic throughput rate. Data can also be segmented per protocol, according to the TCP port number in each header.

Who is it recommended for?

Checkmk has a very wide appeal because of its three editions. Checkmk Raw is free and will appeal to small businesses. This is an adaptation of Nagios Core. The paid version of the system is called Checkmk Enterprise and that is designed for mid-sized and large businesses. Checkmk Cloud is a SaaS option.


  • Provides both network device monitoring and traffic tracking
  • Automatically discovers devices and creates a network inventory
  • Free version available
  • Options for on-premises or SaaS delivery
  • Monitors wireless networks as well as LANs
  • Available for installation on Linux or as an appliance


  • Provides a lot of screens to look through

Start a 30-day free trial.

CheckmkStart 30-day FREE Trial

5. Datadog Network Monitoring – FREE TRIAL

Datadog App Performance

Datadog Network Monitoring supervises the performance of network devices. The service is a cloud-based system that is able to explore a network and detect all connected devices. With the information from this research, the network monitor will create an asset inventory and draw up a network topology map. This procedure means that the system performs its own setup routines.

Features of this package include:

  • Monitors networks anywhere, including remote sites
  • Joins together on-premises and cloud-based resource monitoring
  • Integrates with other Datadog modules, such as log management
  • Offers an overview of all network performance and drill-down details of each device
  • Facilitates troubleshooting by identifying performance dependencies
  • Includes DNS server monitoring
  • Gathers SNMP device reports
  • Blends performance data from many information sources
  • Includes data flow monitoring
  • Offers tag-based packet analysis utilities in the dashboard
  • Integrates protocol analyzers
  • Performance threshold baselining based on machine learning
  • Alerts for warnings over evolving performance issues
  • Packages offer network performance monitoring tools (traffic analysis) or network device monitoring
  • Subscription charges with no startup costs

Why do we recommend it?

Datadog Network Monitoring services are split into two modules that are part of a cloud platform of many system monitoring and management tools. These two packages are called Network Performance Monitoring and Network Device Monitoring, which are both subscription services. While the device monitoring package works through SNMP, the performance monitor measures network traffic levels.

The autodiscovery process is ongoing, so it spots any changes you make to your network and instantly updates the inventory and the topology map. The service can also identify virtual systems and extend monitoring of links out to cloud resources.

Datadog Network Monitoring

Datadog Network Monitoring provides end-to-end visibility of all connections, which are also correlated with performance issues highlighted in log messages. The dashboard for the system is resident in the cloud and accessed through any standard browser. This centralizes network performance data from many sources and covers the entire network, link by link and end to end.

You can create custom graphs, metrics, and alerts in an instant, and the software can adjust them dynamically based on different conditions. Datadog prices start from free (up to five hosts), Pro $15/per host, per month and Enterprise $23 /per host, per month.

Who is it recommended for?

The two Datadog network monitoring packages are very easy to sign up for. They work well together to get a complete view of network activities. The pair will discover all of the devices on your network and map them, then startup automated monitoring. These are very easy-to-use systems that are suitable for use by any size of business.


  • Has one of the most intuitive interfaces among other network monitoring tools
  • Cloud-based SaaS product allows monitoring with no server deployments or onboarding costs
  • Can monitor both internally and externally giving network admins a holistic view of network performance and accessibility
  • Supports auto-discovery that builds network topology maps on the fly
  • Changes made to the network are reflected in near real-time
  • Allows businesses to scale their monitoring efforts reliably through flexible pricing options


  • Would like to see a longer trial period for testing

Start a 14-day free trial.

DatadogStart a 14-day FREE Trial

6. ManageEngine OpManager – FREE TRIAL

ManageEngine OpManager Linux Network Monitoring

At its core, ManageEngine OpManager is infrastructure management, network monitoring, and application performance management “APM” (with APM plug-in) software.

Key Features:

  • Includes server monitoring as well as network monitoring
  • Autodiscovery function for automatic network inventory assembly
  • Constant checks on device availability
  • A range of network topology map options
  • Automated network mapping
  • Performs an SNMP manager role, constantly polling for device health statuses
  • Receives SNMP Traps and generates alerts when device problems arise
  • Implements performance thresholds and identifies system problems
  • Watches over resource availability
  • Customizable dashboard with color-coded dials and graphs of live data
  • Forwards alerts to individuals by email or SMS
  • Available for Windows Server and Linux
  • Can be enhanced by an application performance monitor to create a full stack supervisory system
  • Free version available
  • Distributed version to supervise multiple sites from one central location

Why do we recommend it?

ManageEngine OpManager is probably the biggest threat to SolarWind’s leading position. This package monitors servers as well as networks. This makes it a great system for monitoring virtualizations.

When it comes to network management tools, this product is well balanced when it comes to monitoring and analysis features.

The solution can manage your network, servers, network configuration, and fault & performance; It can also analyze your network traffic. To run Manage Engine OpManager, it must be installed on-premises.

A highlight of this product is that it comes with pre-configured network monitor device templates. These contain pre-defined monitoring parameters and intervals for specific device types.
The essential edition product can be purchased for $595 which allows up to 25 devices.

Who is it recommended for?

A nice feature of OpManager is that it is available for Linux as well as Windows Server for on-premises installation and it can also be used as a service on AWS or Azure for businesses that don’t want to run their own servers. The pricing for this package is very accessible for mid-sized and large businesses. Small enterprises with simple networks should use the Free edition, which is limited to covering a network with three connected devices.


  • Designed to work right away, features over 200 customizable widgets to build unique dashboards and reports
  • Leverages autodiscovery to find, inventory, and map new devices
  • Uses intelligent alerting to reduce false positives and eliminate alert fatigue across larger networks
  • Supports email, SMS, and webhook for numerous alerting channels
  • Integrates well in the ManageEngine ecosystem with their other products


  • Is a feature-rich tool that will require a time investment to properly learn

Start 30-day free trial.

ManageEngine OpManagerDownload a 30-day FREE Trial

7. NinjaOne RMM – FREE TRIAL

NinjaOne Endpoint Management

NinjaOne is a remote monitoring and management (RMM) package for managed service providers (MSPs). The system reaches out to each remote network through the installation of an agent on one of its endpoints. The agent acts as an SNMP Manager.

Key Features:

  • Based on the Simple Network Management Protocol
  • SNMP v1, 2, and 3
  • Device discovery and inventory creation
  • Continuous status polling for network devices and endpoints
  • Live traffic data with NetFlow, IPFIX, J-Flow, and sFlow
  • Traffic throughput graphs
  • Customizable detail display
  • Performance graphs
  • Switch port mapper
  • Device availability checks
  • Syslog processing for device status reports
  • Customizable alerts
  • Notifications by SMS or email
  • Related endpoint monitoring and management

Why do we recommend it?

NinjaOne RMM enables each technician to support multiple networks simultaneously. The alerting mechanism in the network monitoring service means that you can assume that everything is working fine on a client’s system unless you receive a notification otherwise. The network tracking service sets itself up automatically with a discovery routine.

The full NinjaOne RMM package provides a full suite of tools for administering a client’s system. The network monitoring service is part of that bundle along with endpoint monitoring and patch management.

The Ninja One system onboards a new client site automatically through a discovery service that creates both hardware and software inventories. The data for each client is kept separate in a subaccount. Technicians that need access to that client’s system for investigation need to be set up with credentials.

The network monitoring system provides both device status tracking and network traffic analysis. The service provides notifications if a dive goes offline or throughput drops.

Who is it recommended for?

This service is built with a multi-tenant architecture for use by managed service providers. However, IT departments can also use the system to manage their own networks and endpoints. The service is particularly suitable for simultaneously monitoring multiple sites. The console for the RMM is based in the cloud and accessed through any standard Web browser.


  • A cloud-based package that onboards sites through the installation of an agent
  • Auto discovery for network devices and endpoints
  • Network device status monitoring
  • Network traffic analysis
  • Syslog message scanning


  • No price list

NinjaOne doesn’t publish a price list so you start your buyer’s journey by accessing a 14-day free trial.

NinjaOneStart a 14-day FREE Trial

8. Site24x7 Network Monitoring – FREE TRIAL

Site24x7 Network Performance Monitor

Site24x7 is a monitoring service that covers networks, servers, and applications. The network monitoring service in this package starts off by exploring the network for connected devices. IT logs its findings in a network inventory and draws up a network topology map.

Key Features:

  • A hosted cloud-based service that includes CPU time and performance data storage space
  • Can unify the monitoring of networks on site all over the world
  • Uses SNMP to check on device health statuses
  • Gives alerts on resource shortages, performance issues, and device problems
  • Generates notifications to forward alerts by email or SMS
  • Root cause analysis features
  • Autodiscovery for a constantly updated network device inventory
  • Automatic network topology mapping
  • Includes internet performance monitoring for utilities such as VPNs
  • Specialized monitoring routines for storage clusters
  • Monitors boundary and edge services, such as load balancers
  • Offers overview and detail screens showing the performance of the entire network and also individual devices
  • Includes network traffic flow monitoring
  • Facilities for capacity planning and bottleneck identification
  • Integrates with application monitoring services to create a full stack service

Why do we recommend it?

Site24x7 Network Monitoring is part of a platform that is very similar to Datadog. A difference lies in the number of modules that Site24x7 offers – it has far fewer than Datadog. Site24x7 bundles its modules into packages with almost all plans providing monitoring for networks, servers, services, applications, and websites. Site24x7 was originally developed to be a SaaS plan for ManageEngine but then was split out into a separate brand, so there is very solid expertise behind this platform.

The Network Monitor uses procedures from the Simple Network Management Protocol (SNMP) to poll devices every minute for status reports. Any changes in the network infrastructure that are revealed by these responses update the inventory and topology map.

The results of the device responses are interpreted into live data in the dashboard of the monitor. The dashboard is accessed through any standard browser and its screens can be customized by the user.

The SNMP system empowers device agents to send out a warning without waiting for a request if it detects a problem with the device that it is monitoring. Site24x7 Infrastructure catches these messages, which are called Traps, and generates an alert. This alert can be forwarded to technicians by SMS, email, voice call, or instant messaging post.

The Network Monitor also has a traffic analysis function. This extracts throughput figures from switches and routers and displays data flow information in the system dashboard. This data can also be used for capacity planning.

Who is it recommended for?

The plans for Site24x7 are very reasonably priced, which makes them accessible to businesses of all sizes. Setup for the system is automated and much of the ongoing monitoring processes are carried out without any manual intervention.


  • One of the most holistic monitoring tools available, supporting networks, infrastructure, and real user monitoring in a single platform
  • Uses real-time data to discover devices and build charts, network maps, and inventory reports
  • Is one of the most user-friendly network monitoring tools available
  • User monitoring can help bridge the gap between technical issues, user behavior, and business metrics
  • Supports a freeware version for testing


  • Is a very detailed platform that will require time to fully learn all of its features and options

Site24x7 costs $9 per month when paid annually. It is available for a free trial.

Site24x7Get the FREE Trial

9. Atera – FREE TRIAL

Atera Screenshot

Atera is a package software that was built for managed service providers. It is a SaaS platform and it includes professional service automation (PSA) and remote monitoring and management (RMM) systems.

Why do we recommend it?

Atera is a package of tools for managed service providers (MSPs). Alongside remote network monitoring capabilities, this package provides automated monitoring services for all IT operations. The package also includes some system management tools, such as a patch manager. Finally, the Atera platform offers Professional Services Automation (PSA) tools to help the managers of MSPs to run their businesses.

The network monitoring system operates remotely through an agent that installs on Windows Server. The agent enables the service to scour the network and identify all of the network devices that run it. This is performed using SNMP, with the agent acting as the SNMP Manager.

The SNMP system enables the agent to spot Traps, which warn of device problems. These are sent to the Atera network monitoring dashboard, where they appear as alerts. Atera offers an automated topology mapping service, but this is an add-on to the main subscription packages.

Who is it recommended for?

Atera charges for its platform per technician, so it is very affordable for MSPs of all sizes. This extends to sole technicians operating on a contract basis and possibly fielding many small business clients.


  • Remote automated network discovery
  • Network performance monitoring with SNMP
  • Alerts for notified device problems
  • Also includes remote system management tools
  • Scalable pricing with three plan levels
  • 30-day free trial


  • Network mapping costs extra

You can start a 30-day free trial.

AteraStart 30-day Free Trial

10. ManageEngine RMM Central – FREE TRIAL

ManageEngine RMM Central

ManageEngine RMM Central provides sysadmins with everything they need to support their network. Automated asset discovery makes deployment simple, allowing you to collect all devices on your network by the end of the day.

Key Features

  • Automated network monitoring and asset discovery
  • Built-in remote access with various troubleshooting tools
  • Flexible alert integrations

With network and asset metrics collected, administrators can quickly see critical insights automatically generated by the platform. With over 100 automated reports it’s easy to see exactly where your bottlenecks are and what endpoints are having trouble.

Administrators can configure their own SLAs with various automated alert options and even pair those alerts with other automation that integrate into their helpdesk workflow.


  • Uses a combination of packet sniffing, WMI, and SNMP to report network performance data
  • Fully customizable dashboard is great for both lone administrators as well as NOC teams
  • Drag and drop editor makes it easy to build custom views and reports
  • Supports a wide range of alert mediums such as SMS, email, and third-party integrations into platforms like Slack


  • Is a very comprehensive platform with many features and moving parts that require time to learn

Start a 30-day free trial.

source :

Running Remote Commands

Article 07/03/2023

In this article

  1. Windows PowerShell remoting without configuration
  2. Windows PowerShell remoting
  3. See Also

You can run commands on one or hundreds of computers with a single PowerShell command. Windows PowerShell supports remote computing using various technologies, including WMI, RPC, and WS-Management.

PowerShell supports WMI, WS-Management, and SSH remoting. In PowerShell 7 and higher, RPC is supported only on Windows.

For more information about remoting in PowerShell, see the following articles:

Windows PowerShell remoting without configuration

Many Windows PowerShell cmdlets have the ComputerName parameter that enables you to collect data and change settings on one or more remote computers. These cmdlets use varying communication protocols and work on all Windows operating systems without any special configuration.

These cmdlets include:

Typically, cmdlets that support remoting without special configuration have the ComputerName parameter and don’t have the Session parameter. To find these cmdlets in your session, type:


Get-Command | Where-Object {
    $_.Parameters.Keys -contains "ComputerName" -and
    $_.Parameters.Keys -notcontains "Session"

Windows PowerShell remoting

Using the WS-Management protocol, Windows PowerShell remoting lets you run any Windows PowerShell command on one or more remote computers. You can establish persistent connections, start interactive sessions, and run scripts on remote computers.

To use Windows PowerShell remoting, the remote computer must be configured for remote management. For more information, including instructions, see About Remote Requirements.

Once you have configured Windows PowerShell remoting, many remoting strategies are available to you. This article lists just a few of them. For more information, see About Remote.

Start an interactive session

To start an interactive session with a single remote computer, use the Enter-PSSession cmdlet. For example, to start an interactive session with the Server01 remote computer, type:


Enter-PSSession Server01

The command prompt changes to display the name of the remote computer. Any commands that you type at the prompt run on the remote computer and the results are displayed on the local computer.

To end the interactive session, type:



For more information about the Enter-PSSession and Exit-PSSession cmdlets, see:

Run a Remote Command

To run a command on one or more computers, use the Invoke-Command cmdlet. For example, to run a Get-UICulture command on the Server01 and Server02 remote computers, type:


Invoke-Command -ComputerName Server01, Server02 -ScriptBlock {Get-UICulture}

The output is returned to your computer.


LCID    Name     DisplayName               PSComputerName
----    ----     -----------               --------------
1033    en-US    English (United States)
1033    en-US    English (United States)

Run a Script

To run a script on one or many remote computers, use the FilePath parameter of the Invoke-Command cmdlet. The script must be on or accessible to your local computer. The results are returned to your local computer.

For example, the following command runs the DiskCollect.ps1 script on the remote computers, Server01 and Server02.


Invoke-Command -ComputerName Server01, Server02 -FilePath c:\Scripts\DiskCollect.ps1

Establish a Persistent Connection

Use the New-PSSession cmdlet to create a persistent session on a remote computer. The following example creates remote sessions on Server01 and Server02. The session objects are stored in the $s variable.


$s = New-PSSession -ComputerName Server01, Server02

Now that the sessions are established, you can run any command in them. And because the sessions are persistent, you can collect data from one command and use it in another command.

For example, the following command runs a Get-HotFix command in the sessions in the $s variable and it saves the results in the $h variable. The $h variable is created in each of the sessions in $s, but it doesn’t exist in the local session.


Invoke-Command -Session $s {$h = Get-HotFix}

Now you can use the data in the $h variable with other commands in the same session. The results are displayed on the local computer. For example:


Invoke-Command -Session $s {$h | where {$_.InstalledBy -ne "NT AUTHORITY\SYSTEM"}}

Advanced Remoting

PowerShell includes cmdlets that allow you to:

  • Configure and create remote sessions both from the local and remote ends
  • Create customized and restricted sessions
  • Import commands from a remote session that actually run implicitly on the remote session
  • Configure the security of a remote session

PowerShell on Windows includes a WSMan provider. The provider creates a WSMAN: drive that lets you navigate through a hierarchy of configuration settings on the local computer and remote computers.

For more information about the WSMan provider, see WSMan Provider and About WS-Management Cmdlets, or in the Windows PowerShell console, type Get-Help wsman.

For more information, see:

For help with remoting errors, see about_Remote_Troubleshooting.

See Also

Source :

Keep removed apps from returning during an update

Article 02/24/2023

In this article

  1. Create registry keys for deprovisioned apps
  2. Package names for apps provisioned in Windows 10, version 1709
  3. Registry keys for provisioned apps

When you update a computer running Windows 10, version 1703 or 1709, you might see provisioned apps that you previously removed post-update. This can happen if the computer was offline when you removed the apps. Windows 10, version 1803 has fixed this issue.


  • This issue only occurs after a feature update (from one version to the next), not monthly updates or security-related updates.
  • This only applies to first-party apps that shipped with Windows 10. This doesn’t apply to third-party apps, Microsoft Store apps, or LOB apps.
  • This issue can occur whether you removed the app using Remove-appxprovisionedpackage or Get-AppxPackage -allusers | Remove-AppxPackage -Allusers.

To remove a provisioned app, you need to remove the provisioning package. The apps might reappear if you removed the packages in one of the following ways:

  • If you removed the packages while the wim file was mounted when the device was offline.
  • If you removed the packages by running a PowerShell cmdlet on the device while Windows was online. Although the apps won’t appear for new users, you’ll still see the apps for the user account you signed in as.

When you remove a provisioned app, we create a registry key that tells Windows not to reinstall or update that app the next time Windows is updated. If the computer isn’t online when you deprovision the app, then we don’t create that registry key. (This behavior is fixed in Windows 10, version 1803. If you’re running Windows 10, version 1709, apply the latest security update to fix it.)


If you remove a provisioned app while Windows is online, it’s only removed for new users—the user that you signed in as will still have that provisioned app. That’s because the registry key created when you deprovision the app only applies to new users created after the key is created. This doesn’t happen if you remove the provisioned app while Windows is offline.

To prevent these apps from reappearing at the next update, manually create a registry key for each app, then update the computer.

Create registry keys for deprovisioned apps

Use the following steps to create a registry key:

  1. Identify any provisioned apps you want removed. Record the package name for each app.
  2. Create a .reg file to generate a registry key for each app. Use this list of Windows 10, version 1709 registry keys as your starting point.
    1. Paste the list of registry keys into Notepad (or a text editor).
    2. Remove the registry keys belonging to the apps you want to keep. For example, if you want to keep the Bing Weather app, delete this registry key:YAMLCopyHKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Appx\A ppxAllUserStore\Deprovisioned\Microsoft.BingWeather_8wekyb3d8bbwe]
    3. Save the file with a .txt extension, then right-click the file and change the extension to .reg.
  3. Double-click the .reg file to create the registry keys. You can see the new keys in HKLM\path-to-reg-keys.

You’re now ready to update your computer. After the update, check the list of apps in the computer to confirm the removed apps are still gone.

Package names for apps provisioned in Windows 10, version 1709

Displayed app namePackage name

Registry keys for provisioned apps


Windows Registry Editor Version 5.00
;1709 Registry Keys





































Get-AppxPackage Get-AppxPackage -allusers Remove-AppxPackage

Source :

How to Disable or Remove OneDrive on Windows 11


Windows 11 comes with OneDrive pre-installed, but you don’t have to live with it if you don’t want to.

In newer versions of Windows, Microsoft added OneDrive to its “out-of-box experience,” meaning you get the app on your system from day one. OneDrive is a great tool for keeping your files stored in the cloud, but some users have their own preferred cloud storage app or want to keep everything on local storage.

If you feel that OneDrive serves no useful purpose to you, it is possible to disable the app. This post will discuss the methods to disable the app on your system. In addition, you will learn multiple ways to completely remove it.

Why Should You Disable OneDrive?

You may not want to keep a cloud backup of sensitive files related to work or personal use cases. One another issue is that OneDrive runs as soon as you boot your system. It continues to run in the background and consumes system and network resources in the process.

If you have a low-spec system or metered network connection, you can relate to this issue. So, it would be a good idea to disable or remove the app from your system in these circumstances.

Does Microsoft OneDrive Impact PC Performance?

OneDrive launches as soon as your system boots up. It tries to sync your documents to the cloud and runs in the background. Systems that have bare minimum compute resources can struggle with performance.

As such, if your PC isn’t the fastest out there, disabling OneDrive or getting rid of it entirely can help squeeze some precious processing power out of your system for other tasks.

How to Disable OneDrive on Windows 11

There are multiple ways to disable OneDrive on your system. You can disable the service from running at startup, disable it via the Group Policy Editor, or you can unlink your account from it.

1. How to Stop OneDrive From Launching at Startup

To disable OneDrive from launching at startup, do as follows:

  1. Go to the system tray icon area and click on the arrow icon. Then click on the OneDrive system tray icon to reveal the settings.
  2. Click on the gear icon and then select settings from the context menu.
  3. Switch to the Settings tab. Uncheck the Start OneDrive automatically when I sign in to the Windows option under the General section.Disable OneDrive From Launching At Startup
  4. Close the window. Now OneDrive won’t start automatically when you boot your PC up.

If you unlink your OneDrive account, the app won’t be able to sync your files anymore. To unlink your account, repeat the following steps.

  1. Open the OneDrive app from the system tray icon. Click on the gear icon and then click on the Settings option.
  2. Find the Unlink this PC option present under the Accounts tab.Unlink-Your-OneDrive-Account-1
  3. Follow the on-screen prompts to unlink your account and close the Window.

3. How to Disable OneDrive Using the Group Policy Editor

Windows users who own an Enterprise or Professional copy can use the Group Policy Editor to disable OneDrive. If you’re not on either of those versions, you’ll need to learn how to access the Group Policy Editor on Windows Home before you try these steps.

  1. Press Win + R to launch the Run command box on your system. Input gpedit.msc and press the Enter key.
  2. Group Policy Editor will launch.
  3. Navigate to Computer Configuration > Administrative Templates > Windows Components > OneDrive.
  4. Once you are inside the OneDrive folder, find the Prevent the usage of OneDrive for file storage policy.Disable OneDrive Using Group Policy Editor
  5. Double-click on it to edit the policy. A new window with detailed settings will pop up.
  6. Click on the Disabled radio button and then click the Apply button.
  7. Click on the OK button and exit the Group Policy Editor.

How to Remove OneDrive From Windows 11

If you’d rather just get rid of the app entirely, here are a few methods to remove OneDrive from your computer.

1. How to Uninstall OneDrive Using the Settings App

To remove OneDrive using the Settings app, do as follows:

  1. Press Win + I to launch the Settings app. Then navigate to the left-hand side menu and click on Apps.
  2. Then click on the Installed apps option in the Apps section.
  3. Scroll down and locate Microsoft OneDrive app in the list.
  4. Click on the three dots and select the Uninstall option.Uninstall OneDrive Using the Settings App
  5. Confirm your action and click on the Uninstall button again.
  6. Now, follows the on-screen prompts to remove the app from your system.

2. How to Uninstall OneDrive Using the Command Prompt

To remove OneDrive using the command prompt, do as follows:

  1. Press the Win key and search command prompt. Right-click on the first result and select the Run as administrator option.
  2. The command prompt will launch. Now, input the following command in the terminal: TASKKILL /f /im OneDrive.exe
  3. Once the command finishes executing, enter the uninstallation command: %systemroot%\SysWOW64\OneDriveSetup.exe /uninstallUninstall OneDrive Using CMD
  4. Wait for the execution to complete. CMD will not display any message about the uninstallation command.
  5. Exit the command prompt window. OneDrive won’t bother you anymore.

3. How to Uninstall OneDrive Using the PowerShell

To remove OneDrive using PowerShell, do as follows:

  1. Press the Win key and search for PowerShell. Right-click on the first search result and click on the Run as administrator option.
  2. PowerShell will launch. Now input the following command: winget uninstall onedriveUninstall OneDrive Using Powershell
  3. Press the Enter key to execute the command. You will see a successfully uninstalled message if the command executes without any error.
  4. Now, exit the PowerShell window.

4. How to Uninstall OneDrive Using a Batch Script

The above-mentioned processes uninstall the app but do not delete the remaining traces of the OneDrive app. However, there is a batch script that you can use to uninstall the app as well as remove all the traces of OneDrive from your system.

To remove OneDrive using a batch script, do as follows:

  1. Press the Win key and search for Notepad on your system. Click on the first result to launch the notepad app.
  2. Now, copy the following code into the notepad app window. Make sure to recheck the document for missing lines of code, if any.@echo off

    set x86="%SYSTEMROOT%\System32\OneDriveSetup.exe"
    set x64="%SYSTEMROOT%\SysWOW64\OneDriveSetup.exe"

    echo Closing OneDrive process.
    taskkill /f /im OneDrive.exe > NUL 2>&1
    ping -n 5 > NUL 2>&1

    echo Uninstalling OneDrive.
    if exist %x64% (
    %x64% /uninstall
    ) else (
    %x86% /uninstall
    ping -n 5 > NUL 2>&1

    echo Removing OneDrive leftovers.
    rd "%USERPROFILE%\OneDrive" /Q /S > NUL 2>&1
    rd "C:\OneDriveTemp" /Q /S > NUL 2>&1
    rd "%LOCALAPPDATA%\Microsoft\OneDrive" /Q /S > NUL 2>&1
    rd "%PROGRAMDATA%\Microsoft OneDrive" /Q /S > NUL 2>&1

    echo Removing OneDrive from the Explorer Side Panel.
    REG DELETE "HKEY_CLASSES_ROOT\CLSID\{018D5C66-4533-4307-9B53-224DE2ED1FE6}" /f > NUL 2>&1
    REG DELETE "HKEY_CLASSES_ROOT\Wow6432Node\CLSID\{018D5C66-4533-4307-9B53-224DE2ED1FE6}" /f > NUL 2>&1
  3. Now, navigate to the top area and click on the File option. Select the Save as option from the dropdown menu.Uninstall OneDrive Using batch script
  4. Choose the save location as desktop so that it is easier to find the file.
  5. Input a name that reflects the use case of the .bat file. For example, OneDriveRemovalTool.
  6. Now, click on the Save as type option and select All files from the drop-down list.
  7. Click on the Save button to save your .bat file.
  8. Go to the desktop and right-click on the newly created .bat file. Select the Run as administrator option.
  9. Let it finish execution and restart your computer. OneDrive won’t bug you anymore.

5. How to Uninstall OneDrive Using a Third-party Uninstaller Program

Uninstalling OneDrive using the Windows uninstaller leaves a lot of files and folders behind. In such cases, you can try a third-party uninstaller tool that will clean up everything related to OneDrive.

We will use Revo uninstaller app for this method, but you can use your preferred third-party uninstaller app for Windows if you like.

  1. Open any browser on your system and go to the official Revo uninstaller download page.
  2. Download the free version and install it on your system.
  3. Launch Revo uninstaller. Find OneDrive from the list of installed programs.
  4. Right-click on OneDrive and select the Uninstall option from the context menu.
  5. Uninstall window will pop up. Click on the continue button to proceed.Uninstall OneDrive Using Revo unistaller
  6. After the uninstall completes, select the advanced option to search for files and folders associated with OneDrive.
  7. Follow the on-screen prompts and delete everything. Restart your system for changes to take effect. You won’t find OneDrive anywhere on your system.

OneDrive Won’t Bother You Anymore

These were the steps to disable or remove OneDrive on your Windows machine. If you plan on reusing OneDrive someday, stick with the disabling methods. But if you want to remove it from your system, you can try out any of the uninstallation methods mentioned above.

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WinRM QuickConfig, HowTo Enable via GPO or Remotely on All Servers

Marc Wilson UPDATED: February 3, 2023

Configuring “WinRM Quickconfig” on remote computers can be a little difficult at times, especially if this is your first time using the Windows Remote Management service.

There are several ways to go about enabling winrm quickconfig on remote computers, many admins like to push the task to a GPO and others like to do it through powershell or 3rd Party programs.

We’ll highlight 3 different methods we’ve used in the past to get Windows Remote Management service enabled, along with avoiding the dreaded “WINRM QUICKCONFIG ACCESS DENIED” error that many people get when going through this process.

3 Ways to Remotely Enable WinRM on Windows Clients/Servers:

  1. Download and Run this Free Utility from Solarwinds to activate it on Remote Machines
  2. Setup new Group Policy Object to enable the WinRM Service and Firewall Rules
  3. Use PSEXEC to Remotely Enable on Client Machines

1. Free Utility for Remote Activation

This is by far the easiest way if you’ve already configured the Windows Firewall in your network. Solarwinds has a nifty free tool called “Remote Execution Enabler for PowerShell” that has the functionality to enable and configure WinRm on local and remote hosts within your network.

Its as easy as entering in the IP Address(es) or IP Address Range of all the computers your targeting, than enter credentials that have Administrative Rights to that PC (usually accounts in the Domain Administrators Group will do the trick) and click the “START CONFIGURATION” button:

winrm remote enabler by solarwinds screenshot

When the utility is finished starting the Windows Remote Management services on all IP Addresses or Ranges specified, you will see a green dot with a “Complete” status, as seen below:

completed screen

Grab the little utility from below and give it a go:

Download Free!

2. Setup via Group Policy Object (GPO)

If the above solution didn’t work for you, then setting up a GPO to do all the configuration is the next best thing, as you can assign it to any given computer or OU if necessary. Below are instructions for Windows 2012 R2 Server GPO setup.

  1. Open Group Policy Management from within Administrative Tools folder.
  2. Right-click on the desired OU that you want to create a Group Policy Object for and click on “Create a GPO in this Domain, and Link it here…
  3. Rename the GPO to whatever you would like, “Enable WinRM via GPO” or something along those lines then click OK.
  4. Now that the new GPO has been created, right-click on the Newly created GPO and click “EDIT“.
  5. Expand the Menu tree as follows: Computer Configuration > Policies Administrative Templates: Policy definitions > Windows Components > Windows Remote Management (WinRM) WinRM Service.
  6. Find the setting that says “Allow remote server management through WinRM” and right-click and click “EDIT” to configure the settings. (see image below)
    winrm group policy setting
  7. When the dialog box opens up, click “Enabled” and under the options section, either specify an IP Address range or put an Asterisk “*” to allow all IP addresses to remotely manage the PC. (We recommend specifying an IP Address to reduce any risk of a security compromise of your systems/network).
    config settings
  8. Now lets enable the Windows Remote Mangement (WS-Management) Service to start automatically.
    Go to Computer Configuration >  Preferences > Control Panel Settings > Services and right-click and select “NEW” and the select “Service“.
  9. A New Service Properties window will come up and you will need to change Startup to “Automatic (Delayed Start)” and then in the Service Name dialog box, click the box with the 3 dots in it to the right of the Service name box and select “Windows Remote Management (WS-Management)” and click the Select button.
  10. Once you’ve selected the Service, under the “Service action:” pull down, we’ll want to click “Start service“.
    gpo service setup
  11. Last Step of this Process is to configure the Windows Firewall to Allow the proper ports inbound.Go to Computer Configuration > expand Policies > expand Windows Settings > expand Security Settings > expand Windows Firewall with Advanced Security > expand Windows Firewall with Advanced Security > expand Inbound Rules.Right-click the Inbound Rules node and choose New Rule. (see screenshot below)inbound firewall rule
  12. When the New Inbound Rule wizard box opens, click on the “Predefined” radio button and scroll down to “Windows Remote Management” and click on it. (see screenshot below)predefinied winrm rule
  13. Next we’ll click on the Left Sidebar menu item that says “Predefined Rules” in order to not Allow the Firewall to open this Port to the Public network.When the window opens, uncheck the box that says Public profile next to it, as seen in the image below. This ensures that we only allow WinRM access to the Private and Domain networks.Then Click the Next button:remove public firewall rule
  14. The Last screen of the New Inbound Firewall Wizard will just ask whether to Allow The Connection or block it.Make sure the that “Allow the connection” radio box is checked and click Finish.

    allow connection

At this point, you’ve successfully finished the GPO and you’ll need to wait for the GPO to propagate throughout your network.

3. PSEXEC for WinRM Activation

If either of the two options above don’t work for you, using PSEXEC to remotely enable the service is another option, if you prefer. Here are the relevant commands you will need in order to execute “winrm quickconfig” using PSexec command line utility.

  1. Make sure you have PSEXEC installed on your machine and the proper “PATH” setup within your system variables – this should be automatically added when you install PSEXEC.If you dont have PSEXEC installed yet, grab the download from here (its part of the PSTOOLS package) and install it.
  2. Launch the an elevated “Command Prompt” window using your local/domain administrator account as the user of the target machine/s, to ensure that you have the necessary permissions to configure WinRM remotely on machines in your network.To run “Command Prompt” as a different user, hold the Shift Key down and right-click on the Command Prompt link and click on “Run as Different User” and then enter in a user account that has Administrator Privileges on all computers your targeting.elevated command prompt domain adminlogin
  3. Run one of the following commands below:psexec \\ComputerName -s winrm.cmd quickconfig -q or create a text file with all the computer names you want to target and save them on your C:\ drive and run the command below to enable on all PC’s in the specified text file we just created.Now you can run any one of the commands below depending on what you want to accomplishpsexec @c:\ALLComputerNames.txt -s winrm.cmd quickconfig -q
  4. If all goes well, you’ll see a screen like the one below that confirms everything has been configured properly for WinRM on the remote machine/s.psexec winrm remotely success


is WinRM the same as RDP?

WinRM and RDP are two different systems but they can be used for the same purpose, which is to get remote access to a computer and execute commands. WinRM is a text-based system but RDP shows the Desktop of the remote computer.

Is WinRM a security risk?

WinRM uses HTTP by default and that isn’t secure. However, you can configure the system to use HTTPS for connections and that makes WinRM secure.

Does WinRM use TLS?

WinRM will use Transport Layer Security (TLS) if you specify that it should run its connections with HTTPS.

How does WinRM QuickConfig configure the firewall on the remote computer?

WinRM QuickConfig configures the firewall on the remote computer by adding a rule to allow incoming traffic on the WinRM port (default is 5985).

Is WinRM QuickConfig secure?

WinRM QuickConfig uses the HTTPS protocol to encrypt communication between the remote and local computers, making it secure for remote management.

What are the prerequisites for using WinRM QuickConfig on a remote computer?

The prerequisites for using WinRM QuickConfig on a remote computer include having administrative privileges on both the local and remote computers and having network connectivity between the computers.

How can I verify that WinRM is configured correctly on a remote computer?

To verify that WinRM is configured correctly on a remote computer, you can use the “WinRM Id” command to retrieve information about the remote computer and the WinRM configuration. If the command returns information about the remote computer and the WinRM configuration, it means that WinRM is configured correctly.

Related Articles:

What Is WinRM? Windows Remote Management command-line Utility

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How to Install Windows 11 on Unsupported Hardware (Without TPM & Secure Boot)

June 8, 2023

To install Windows 11 (or upgrade from Windows 10), your computer must meet certain minimum system requirements: TPM 2.0 chip (Trusted Platform Module), UEFI + Secure Boot mode enabled, 3+ GB RAM, at least 64 GB hard drive, and a compatible 1GHz dual-core CPU (not all processors are supported!). Microsoft restricts the installation of Windows 11 to non-compatible devices by performing some pre-installation hardware requirements checks. In this article, we’ll show how to install Windows 11 on unsupported hardware without checking CPU, TPM, Secure Boot, and other requirements.

If your computer does not meet the minimum Windows 11 hardware requirements, you will see the following error during the OS installation:This PC can’t run Windows 11. This PC doesn’t meet the minimum system requirements to install this version of Windows. For more information, visit

To understand what requirements your computer doesn’t meet, check the Windows 11 setup errors in the setuperr.log file. This file contains only Windows installation errors (you can find the complete Windows install log in the setupact.log file, but it is hard to debug it since it is very large).

To open the Windows setup error log, open the command prompt right on the setup screen by pressing Shift + F10 and run this command:

notepad x:\windows\panther\setuperr.log

troubleshoot Windows 11 installation erorrs, minimum system requirement check via setuperr.log

In our case, the error says that there is not enough RAM on the computer (only 2 GB instead of 3 GB):2022-02-02 08:17:57, Error VerifyRAMRequirements: System has INSUFFICIENT system memory: [2048 MB] vs [3686 MB]

Please note that if your computer doesn’t meet several minimal requirements to install Windows, only the first one will be displayed in the setup log. It means that if you fixed or bypassed one of the compatibility errors, another compatibility error will appear in the installation log the next time you run Windows 11 Setup.

After we have added more RAM to the device, another error appeared:2022-02-02 08:43:21, Error VerifyTPMSupported:Tbsi_GetDeviceInfo function failed – 0x8028400f[gle=0x0000007a]

This means that the Windows 11 setup wizard detected there was no TPM chip on the computer.

If you install Windows 11 to a VMWare virtual machine, you can add a virtual TPM chip following the following guide. Another guide is used for Hyper-V VMs.

However, you can continue Windows 11 setup by ignoring one or more of the compatibility requirements.

To do it, use the command prompt on the Windows 11 setup screen:

  1. Run the Registry Editor regedit.exe.
  2. Go to HKEY_LOCAL_MACHINE\SYSTEM\Setup registry key and create a new key with the name LabConfig;
  3. Create reg DWORD parameters with values 1 for those compatibility checks you want to skip during installation.

The following bypass options are available for installing Windows 11 on unsupported hardware:

  • BypassCPUCheck – for incompatible CPUs
  • BypassTPMCheck – without a TPM 2.0+ chip
  • BypassRAMCheck – to skip minimum RAM check
  • BypassSecureBootCheck – for Legacy BIOS devices (or UEFI firmware with Secure Boot disabled)
  • BypassStorageCheck – to minimal bypass system drive size check

For example, in order not to check the TPM module during installation, create the BypassTPMCheck registry parameter with the value 1. You can do it using the graphical Registry Editor or with the command:

reg add HKLM\SYSTEM\Setup\LabConfig /v BypassTPMCheck /t REG_DWORD /d 1

windows 11 setup screen: bypass unsupported device checks using the bypasstpmcheck parameter under the reg key labconfig

In the same way, create other registry parameters for the checks you want to skip when installing Windows 11.

Then get back to Windows 11 setup window, go one step back, and continue with a typical Windows installation without compatibility checks.

You can modify Windows 11 installation ISO image so that all checks (TPM, SecureBoot, disk size, RAM, CPU) are skipped during OS installation. To do it, create a text file AutoUnattend.xml with the following contents:<unattend xmlns=”urn:schemas-microsoft-com:unattend”> <settings pass=”windowsPE”> <component name=”Microsoft-Windows-Setup” processorArchitecture=”amd64″ publicKeyToken=”31bf3856ad364e35″ language=”neutral” versionScope=”nonSxS” xmlns:wcm=”” xmlns:xsi=””> <RunSynchronous> <RunSynchronousCommand wcm:action=”add”> <Order>1</Order> <Path>reg add HKLM\System\Setup\LabConfig /v BypassTPMCheck /t reg_dword /d 0x00000001 /f</Path> </RunSynchronousCommand> <RunSynchronousCommand wcm:action=”add”> <Order>2</Order> <Path>reg add HKLM\System\Setup\LabConfig /v BypassSecureBootCheck /t reg_dword /d 0x00000001 /f</Path> </RunSynchronousCommand> <RunSynchronousCommand wcm:action=”add”> <Order>3</Order> <Path>reg add HKLM\System\Setup\LabConfig /v BypassRAMCheck /t reg_dword /d 0x00000001 /f</Path> </RunSynchronousCommand> <RunSynchronousCommand wcm:action=”add”> <Order>5</Order> <Path>reg add HKLM\System\Setup\LabConfig /v BypassCPUCheck /t reg_dword /d 0x00000001 /f</Path> </RunSynchronousCommand> <RunSynchronousCommand wcm:action=”add”> <Order>4</Order> <Path>reg add HKLM\System\Setup\LabConfig /v BypassStorageCheck /t reg_dword /d 0x00000001 /f</Path> </RunSynchronousCommand> </RunSynchronous> <UserData> <ProductKey> <Key></Key> </ProductKey> </UserData> </component> </settings> </unattend>

autounattend.xml bypass windows 11 hardware requirements

If you want to disable Microsoft online account creation screen, add the following component section to the file:<component name=”Microsoft-Windows-Shell-Setup” processorArchitecture=”amd64″ publicKeyToken=”31bf3856ad364e35″ language=”neutral” versionScope=”nonSxS” xmlns:wcm=”” xmlns:xsi=””> <OOBE> <HideOnlineAccountScreens>true</HideOnlineAccountScreens> <HideWirelessSetupInOOBE>true</HideWirelessSetupInOOBE> <ProtectYourPC>3</ProtectYourPC> </OOBE> </component>

Copy this file to the root of your Windows 11 USB installation media.

If you want to add an answer file to Windows 11 ISO image, extract its contents to any folder on your computer, copy AutoUnattend.xml to the same directory, and rebuild the ISO image.

I used free DISM++ (Toolkit -> ISO maker) to create the custom Windows 11 ISO image.

dism ++ modify windows iso image add answer file autounattend.xml

Then no hardware compatibility checks will be performed during Windows 11 setup.

Also, you can use the new Rufus version to create installation USB flash drives. It contains a special option: Extended Windows 11 Installation (no TPM/no Secure Boot/8Gb- RAM). This option allows you to create an image to install Windows 11 without checking TPM and Secure Boot:

rufus create installation media without TPM ans secure boot checks

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Know Your Malware Part Two – Hacky Obfuscation Techniques

Ram Gall
November 1, 2023

In the first post in this series, we covered common PHP encoding techniques and how they’re used by malware to hide from security analysts and scanners. In today’s post, we’re going to dive a little bit deeper into other obfuscation techniques that make use of other features available in PHP.

Obfuscation Redux

In the first post in this series, we defined Obfuscation as the process of concealing the purpose or functionality of code or data so that it evades detection and is more difficult for a human or security software to analyze, but still fulfills its intended purpose. One of the main contributing factors to the popularity of PHP is its ease of use, but the same functionality that makes it easy to use also makes it easy to abuse, often in ways that were never intended.

The techniques covered in this post are often simpler and “hackier” than the ones listed in the previous article, and most of them are less reliable as indicators of malicious activity individually, as several of them typically need to be combined in order to achieve sufficient obfuscation. These techniques are also often easier for a human analyst to spot, but they are also more difficult to detect using scanning tools due to the wide variety of permutations available. Such simpler obfuscation methods can also be creatively combined with encoding techniques, granting malware authors a formidable array of tactics to avoid detection.

While it is not practical to cover every possible technique in active use, this article will detail the more commonly found methods, and help illustrate the wide range of possibilities when decoding obfuscated malware. Several of the methods we will cover today, such as comment abuse, can be combined into almost infinite variations with minute changes, thus rendering them completely undetectable to traditional hash-based malware scanning and even partially slowing down regular expression-based scanning of the type used by Wordfence.

Fortunately, while these methods do make analysis more difficult, and can slow down scanning, their presence in certain combinations is a strong signal of malicious activity, and the malware detection signatures used by the Wordfence plugin and Wordfence CLI are tuned to detect these combinations with astoundingly few false positives. Wordfence CLI in particular is useful in these cases, as it is highly performant and can run multithreaded jobs, compensating for any speed penalties imposed by these techniques.

Comment Abuse

PHP has several methods of adding code comments that you may already be familiar with. Well-commented code is considered a best practice, as it makes it much easier to maintain software and pay off technical debt, but comments can also be used for illicit purposes.

PHP uses three styles of comments:

//, denoting a single line comment that ends on the next line.

#, likewise a single line comment that ends on the next line, though this is less common than ‘//’.

/*, the beginning of a multiline comment, which can only closed with */.

Multiline comments are particularly useful to malware authors because they are ignored by PHP, and do not have to extend over multiple lines. This means that an attacker can “break up” their code to evade scanners using comments. For instance, the following code block prints “Hello, World!”:

1234<?phpecho/*blah*/"Hello, World!"/*blah*/;

While this is a very basic example, more complicated examples can be found in real malware, such as the following snippet, which makes use of several additional obfuscation techniques, including octal escape sequences and invisible null bytes:

12,<?php        function/*ti*/ed_ixpn(){     echo/* o_lpl*/20508;  }$disdcrxh_/* ohgvr*/= 'disdcrxh_'/*  _jnsm  */^       '';$zggkgqda= "\146".     "\151"$disdcrxh_(361-253)   ./* qts   */"e"."_".$disdcrxh_(564-452)/* rxw*/.     $disdcrxh_(1006-889)     . "t".$disdcrxh_(952-857) ./*  w  */"c".$disdcrxh_(111) ./*fcup  */"n".$disdcrxh_(162-46)/*   djtrl   */./*  pwdn  */"e".$disdcrxh_(407-297)      .      $disdcrxh_(854-738) . $disdcrxh_(115);

While we’re not going to fully analyze this malware today, it already presents problems for many scanners. For instance, a scanner searching for the very first line of code, function ed_ixpn() would fail to find it because of the comments. While detection using regular expressions, such as the ones used by the Wordfence Plugin scanner and Wordfence CLI are capable of detecting malware of this type, it still imposes a performance penalty on detection due to the enormous number of possible variations.

Concatenation Catastrophe

PHP makes string concatenation very simple via the dot . operator. This allows programmers to join two separate strings with minimal hassle. For instance, the following code outputs “Hello, World!”:

1<?php echo“He”.”llo,”.”wor”.”ld”;

There are a large number of legitimate use cases for string concatenation, so it’s generally only an indicator of malicious activity when combined with several other obfuscation techniques. The malware sample we shared earlier provides a good example of this, with octal encoding concatenated with the return values of various functions, which we’ll get to in a later section.

Index Fun

PHP, like most languages, stores text strings as arrays of characters, each with a defined position or index. This makes it possible to assemble arbitrary commands and data from a string containing the required characters, using the array index of each character and the concatenation operator. For instance, the following code prints “Hello, World!”:

1234<?php$string="Wow, what a cool Helpful research device!";echo$string[17].$string[18].$string[19].$string[19].$string[1].$string[3].$string[4].$string[0].$string[1].$string[25].$string[15].$string[34].$string[40];

PHP arrays start with an index of 0, meaning that $string[0] in the example above would be “W”, the first letter of “Wow, what a cool Helpful research device!”. By concatenating letters from different parts of that text string, it’s possible to assemble an entirely different text string.

This method can be very helpful for hiding the underlying text being assembled from human researchers and security scan tools alike, and though it does have the occasional legitimate use in selecting chunks of text, when used extensively it is a strong indicator of malicious activity, though it typically needs to be combined with additional techniques such as evaluating the resulting string or passing it to a function.

Math, Not Even Once

PHP allows mathematical operations within other functionality. One of the interesting features in the malware snippet – $disdcrxh_(564-452) – demonstrates this, with it turning out as $disdcrxh_112 due to the subtraction of 564 and 452 in the parenthesis. This functionality can likewise be combined with the string index technique mentioned above. For example, the following code prints out “Hello, World!”:

123<?php$string="Wow, what a cool Helpful research device!";echo$string[(15+2)].$string[(20-2)].$string[(10+9)].$string[(29-10)].$string[(5-4)].$string[(1+2)].$string[(2+2)].$string[(5-5)].$string[(12-11)].$string[(5*5)].$string[(5*3)].$string[34].$string[(160/4)];

This adds an additional obfuscation layer that can make it even more difficult to determine the code’s functionality without executing it. However, it is incredibly rare for this type of code to be used legitimately, so the presence of this technique is typically an indicator of malicious activity.

String Reversals

One of the most basic functions in PHP’s text string manipulation libraries is strrev, which is used to reverse strings of text. For instance, the following code snippet prints out “Hello, World!”:

1<?php echostrrev("!dlroW ,olleH");

While not particularly effective at obfuscation on its own, it can be combined with the techniques in this article as well as nearly all of the techniques in our previous article on encoding to make it even more difficult to decode malicious functionality. While it has a number of legitimate use cases, the presence of strrev alongside two or more additional encoding or obfuscation techniques is often a reliable indicator of compromise.

Variable, Dynamic, and Anonymous Functions

PHP has the ability to use variables to store function names as variables and then invoke those functions using the variable. This is widely used by legitimate software, but can also be combined with several other techniques, such as string concatenation, in which case it is often an indicator of malicious activity. For instance, the following code snippet prints out “Hello, World!”:

123<?php $hello='pri'.'ntf';$string='Hello, World!';$hello($string);

This can also be combined with dynamic function invocation using methods such as call_user_func, which accepts a function for its first parameter and any arguments to be passed to that function in subsequent parameters. As with variable function names, this is widely used in legitimate code, but it can still make analysis more difficult, especially for automated tools looking primarily for more basic function call syntax. For example, the following code snippet prints out “Hello, World!”:

1234<?php $hello='pri'.'ntf';$string='Hello, World!';$call='call_user_func';$call($hello, $string);

Finally, PHP also allows for anonymous functions, which are exactly what they sound like – functions without a name. These can be combined with variable assignment as shown:

12345<?php$hello= function() {    printf("Hello, World!");};$hello();

While anonymous functions are widely used in legitimate code, it is possible to use them in combination with other features to make it more difficult for automated scanning tools or human analysts to keep track of code flow and as such are useful for obfuscation.

We’ve begun to combine obfuscation layers in our examples to provide a better picture of the type of obfuscation often found in the wild, and there’s still more to come.

GOTO Labels

One of the oldest and most basic code functions is the goto statement. While some legitimate software still uses GOTO statements, the functionality is considered poor coding practice and is not widely used, though it reflects how the code operates at a fundamental level far more accurately than more modern syntax. Its primary use in obfuscation is similar to comment abuse in that it breaks up the code so that it is more difficult to determine the control flow.

For example, the following code snippet prints out “Hello, World!” if and only if $_GET['input'] is present and set to ‘hello’, otherwise it prints “Sorry”:

123456789101112131415<?php $hello='pri'.'ntf';$string='Hello, World!';if(isset($_GET['input']) && $_GET['input']=='hello'){gotoprintyes;}elsegotoprintno;printyes:echo"Hello, World!";gotoend;printno:echo"Sorry";end:?>

Include/Require of non-PHP files

PHP uses the include and require functions to include and execute code located in a separate file. This is almost universally used, and occasionally the .inc extension is used instead of PHP for files to be included. However, one particular feature that is ripe for abuse is that PHP will include files with any extension and execute them as code. This allows attackers to upload the bulk of their malicious code as a file with an allowed extension, often an image extension such as .ico or .png, and then simply include that file from a loader file with a PHP extension. Inclusion of files without a .php or .inc extension is thus almost always an indicator of malicious activity.

For instance, take the following set of files:


1<?php include('hello.ico');


1<?php echo"Hello, World!";

This will print out “Hello, World” when loader.php is executed, even though hello.ico does not have a PHP extension and would not run as PHP if accessed directly.

Putting it All Together

Here’s an example that makes use of everything we’ve learned today apart from including files:

1234567891011121314151617181920<?php$string=/*blah*/"Wow, what a cool Helpful research device!"/*blah*/;$mashed=$string[(160/4)]./*blah*/$string[34]./*blah*/$string[(5*3)]/*blah*/.$string[(5*5)]/*blah*/.$string[(12-11)]./*blah*/$string[(5-5)]./*blah*//*blah*/$string[(2+2)]./*blah*/$string[(1+2)]./*blah*/$string[(5-4)]/*blah*/.$string[(29-10)]./*blah*/$string[(10+9)]./*blah*/$string[(20-2)]/*blah*/.$string[(15+2)];function/*blah*/echostring(/*blah*/$str/*blah*/){    echo/*blah*/$str;    return/*blah*/;}$rev/*blah*/=/*blah*/function($str){    return/*blah*/strrev($str);};goto/*blah*/dostuff;echo/*blah*/"That didn't work!";dostuff/*blah*/:    call_user_func(/*blah*/'echostring',/*blah*/$rev(/*blah*/$mashed));

It begins with comments breaking up the code as well as the concatenation and string indexing techniques we covered earlier, which assigns “Hello, World!” in reverse, or “!dlroW ,olleH” to the $mashed variable.

A quick glance at the code might lead you to believe that it outputs “That didn’t work!” but thanks to the goto statement that line of code is skipped – such misleading uses are par for the course with malware that uses goto statements.

In the dostuff section, we use call_user_func to call the echostring function, which really just does the same thing as echo but serves as an additional layer of obfuscation to untangle, especially if the function were to be given a less friendly name. The echostring function is fed the output of the anonymous function assigned to the $rev variable, which again simply performs a str_rev on the input. The result is that $mashed is reversed and echoed out as “Hello, World!”. While we have kept the function and variable names relatively relevant for this example, there’s nothing preventing a malware author from naming these functions whatever they want, and indeed, misleading or nonsensical function names are more common than meaningful or useful function names in PHP malware.


In today’s post, we covered a number of the more creative, or “hacky” malware obfuscation techniques in widespread use, and showed examples of how they can be combined to make it difficult to analyze code functionality. All of these techniques can also be combined with the techniques in our previous post on malware obfuscation to make life even more difficult for analysts and security scanners. These two posts cover the most popular obfuscation methods used by PHP malware, but there are even more advanced and sophisticated techniques, including genuine encryption, which we will cover in our next article, alongside less commonly-used functionality.

PHP malware is constantly evolving, and our malware analysts release dozens of detection signatures every month, which can be used by the Wordfence scanner as well as by Wordfence CLI. While the vast majority of new signatures will only be made available to Wordfence PremiumWordfence CareWordfence Response, and the Paid Wordfence CLI Tiers, the free version of Wordfence and Wordfence CLI still offer excellent detection capabilities, and include our broadest signature set, which in our testing detects at least one indicator of compromise on more than 90% of infected sites. We also plan to periodically update our free signature set with signatures that detect the most widespread malware from our full signature set.

Once again, we encourage readers who want to learn more about this to experiment with the various code snippets we have presented. As always, be sure to be careful with any actual malware samples you find and only execute them in a hardened virtual environment, as even PHP malware can be used for local privilege escalation on vulnerable machines.

For security researchers looking to disclose vulnerabilities responsibly and obtain a CVE ID, you can submit your findings to Wordfence Intelligence and potentially earn a spot on our leaderboard.

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Several Critical Vulnerabilities Patched in AI ChatBot Plugin for WordPress

Marco Wotschka
October 25, 2023

On September 28, 2023, the Wordfence Threat Intelligence team initiated the responsible disclosure process for multiple vulnerabilities in AI ChatBot, a WordPress plugin with over 4,000 active installations.

After making our initial contact attempt on September 28th, 2023, we received a response on September 29, 2023 and sent over our full disclosure details. Receipt of the disclosure by the vendor was acknowledged the same day and a fully patched version of the plugin was released on October 19, 2023.

We issued a firewall rule to protect Wordfence Premium, Wordfence Care, and Wordfence Response customers on September 29, 2023. Sites still running the free version of Wordfence will receive the same protection on October 29, 2023.

Please note that these vulnerabilities were originally fixed in 4.9.1 (released October 10, 2023). However, some of them were reintroduced in 4.9.2 and then subsequently patched again in 4.9.3. We recommend that all Wordfence users update to version 4.9.3 or higher immediately.

A complete list of the vulnerabilities we reported is below. Links to Wordfence Intelligence are included where you can find full details:

In this post we will focus on the most impactful vulnerabilities.

Vulnerability Details and Technical Analysis

The AI ChatBot plugin provides website owners with a plug and play chat solution that can be expanded upon with customizable FAQs and custom text responses. It provides website users with an interface that allows them to look up order information, leave contact information for later callbacks and can be integrated with OpenAI’s ChatGPT or Google’s DialogFlow.

A lot of the interactions with the chatbot happen via AJAX actions. Many of these actions were made available to unauthenticated users in order to allow them to interact with the chatbot. Other actions required at least subscriber-level access.

Unauthenticated SQL Injection – CVE-2023-5204

Description: Unauthenticated SQL Injection via qc_wpbo_search_response
Affected Plugin: AI ChatBot
Plugin slug: chatbot
Vendor: QuantumCloud
Affected versions: <= 4.8.9
CVE ID: CVE-2023-5204
CVSS score: 9.8 (Critical)
Researcher: Marco Wotschka
Fully Patched Version: 4.9.1

One of the many vulnerabilities we discovered was an unauthenticated SQL Injection. The following two AJAX actions are used for searches during interactions with the chatbot:

add_action( 'wp_ajax_nopriv_wpbo_search_response', 'qc_wpbo_search_response' );

add_action( 'wp_ajax_wpbo_search_response', 'qc_wpbo_search_response' );

The wp_ajax_nopriv_wpbo_search_response AJAX action can be used by users who are not authenticated to WordPress due to the hook utilizing ‘nopriv’. On the other hand, the standard wp_ajax_wpbo_search_response AJAX action can only be used by authenticated users due to the inherent functionality of AJAX actions.

function qc_wpbo_search_response (shortened for brevity)

The qc_wpbo_search_response function hooked by the aforementioned AJAX actions is used to search within the database for responses containing certain keywords. If the $_POST[‘strid’] parameter is set, a record is retrieved from the wpbot_response table by ID. The $strid variable supplied by the POST parameter can be leveraged for SQL Injection, despite being sanitized using the sanitize_text_field function.

According to the WordPress Developer Resources, the sanitize_text_field function checks for invalid UTF-8; converts single < characters to entities; strips all tags; removes line breaks, tabs, and extra whitespace; strips percent-encoded characters. This does not provide sufficient protection against SQL Injection attempts, and is only intended for Cross-Site Scripting protection. Furthermore, the get_results function used in the above function call does not perform any preparation, nor is there any escaping of the user supplied input passed to the SQL Query. We always recommend the use of the prepare function on SQL queries as it provides adequate escaping on the user-supplied values, which prevents SQL injection from being successful. In addition, ensuring that the $strid is an integer would help prevent a SQL Injection attack from being successful.

The lack of a UNION operation in the above SQL query makes exploiting this vulnerability more difficult, but a time-based blind injection approach using the SLEEP() function and CASE statements can still be used to extract information from the database by observing the duration of individual queries. While tedious, this technique can be used to extract sensitive information from the database. This includes hashed passwords.

Arbitrary File Deletion – CVE-2023-5212

Description: Authenticated (Subscriber+) Arbitrary File Deletion via qcld_openai_delete_training_file
Affected Plugin: AI ChatBot
Plugin slug: chatbot
Vendor: QuantumCloud
Affected versions: <= 4.8.9
CVE ID: CVE-2023-5212
CVSS score: 9.6 (Critical)
Researcher: Marco Wotschka
Fully Patched Version: 4.9.1

The plugin offers the ability to upload training files to OpenAI. An arbitrary file deletion vulnerability existed in the qcld_openai_delete_training_file function invoked via the following AJAX action:


function qcld_openai_delete_training_file

This vulnerable function accepts a file path via the $_POST[‘file’] parameter and checks whether the file exists. If it does, the function adjusts permissions on the file in such a way that it can be removed and proceeds to delete it. This function misses a capability check to ensure that the user performing the action has proper privileges, as well as a nonce check to ensure that the action is performed intentionally. and is thus vulnerable to Missing Authorization and Cross-Site Request Forgery.

Furthermore, no check is performed ensuring that the file is an OpenAI training file and that it resides in a location or directory where training files are expected to be located. This could allow an authenticated attacker with subscriber-level privileges or higher to remove the wp-config.php file of an affected site, which would invoke the WordPress installation script on the next site visit and could lead to a complete site takeover.

The file path passed via the $_POST[‘file’] parameter could also point to a file outside of the affected website, thus enabling the deletion of wp-config.php files of other sites in shared hosting environments. Deleting wp-config.php forces the site into a setup state, at which point an attacker can take over the site by pointing it to a database under their control. Of course, attackers are not limited to deleting PHP files either as long as the web server can change file permissions and delete the file.

Version 4.9.1 removed this function as well as the corresponding AJAX action. Version 4.9.2 reintroduced the vulnerable function and action hook, which were both again removed in version 4.9.3.

Directory Traversal to Arbitrary File Write – CVE-2023-5241

Description: Authenticated (Subscriber+) Directory Traversal to Arbitrary File Write via qcld_openai_upload_pagetraining_file
Affected Plugin: AI ChatBot
Plugin slug: chatbot
Vendor: QuantumCloud
Affected versions: <= 4.8.9
CVE ID: CVE-2023-5241
CVSS score: 9.6 (Critical)
Researcher: Marco Wotschka
Fully Patched Version: 4.9.1

We also discovered an arbitrary file write vulnerability which exists in the qcld_openai_upload_pagetraining_file function. The entire function is rather long which is why we won’t display it here in its entirety.

function qcld_openai_upload_pagetraining_file (shortened for brevity)

The function expects a filename to be passed as a $_POST[‘filename’] parameter, which is sanitized using the sanitize_text_field function. The $file variable is used to determine the location of a file in the wp-content/uploads/qcldopenai_site_training/ directory. If the file exists, the function proceeds to declare a variable called $split_file, creates a file handle $qcld_openai_json_file and opens the file in append mode. This means that the file is not overwritten but anything written to the file is instead appended.

It is not immediately clear what the purpose of this part of the function is since it simply appends the contents that are already in the file to the end of the file until the length of the content that is added exceeds $this->wpaicg_max_file_size or the entire file has been duplicated.

The corresponding if-statement that determines when to terminate writing to the file looks as follows:

if(mb_strlen($qcld_openai_content, '8bit') >$this->wpaicg_max_file_size)

In a default installation $this->wpaicg_max_file_size is not defined and therefore NULL. Hence, in such scenarios the function adds the first line of the file specified by the user to the end of the file. Since NULL is interpreted as zero in a comparison statement like this, any positive file size will suffice to break out of this part of the function.

Unfortunately, this code is vulnerable to Directory Traversal via the filename parameter. If the filename that is passed is a relative path to wp-config.php, the file handle will ultimately point to the site’s wp-config.php file. An authenticated attacker with subscriber-privileges or higher could utilize this fact to append the first line of its content to the file wp-config.php, which would be <?php.

While an attacker does not have any influence on the data that is written, in most cases a <?php could be written to the end of a targeted PHP file, which can lead to catastrophic consequences as the added PHP tag may result in an error such as

Parse error: syntax error, unexpected token "<", expecting end of file

This prevents the site from loading properly and can be used to append to any PHP file (or other files) including those in shared hosting environments leading to Denial of Service (DoS). One way to prevent Directory Traversal is to use the sanitize_file_name function, which removes special characters including slashes and leading dots from the file name.

Version 4.9.1 removed this function as well as the corresponding AJAX action. Version 4.9.2 reintroduced the vulnerable function and action hook, which were both again removed in version 4.9.3.

Numerous Other Missing Authorization and Cross-Site Request Forgery Vulnerabilities

In addition to the vulnerabilities outlined above, we discovered several AJAX actions without proper capability checks, which made it possible for authenticated attackers with minimal access, such as subscribers, to invoke those actions. Several of the functions were also missing nonce verification, which would make it possible for attackers to forge requests on behalf of a site administrator, or any other authenticated user considering capability checks were also missing.

However, these vulnerabilities had minimal impact and led to the exposure of information such as user order details and user names, the download and extraction of a zip used by the plugin (not arbitrary zip files), cache deletion, as well as starting and stopping of search indexing jobs to name a few. The severity of those actions is lower than the ones we detailed above.


September 25-28, 2023 – The Wordfence Threat Intelligence team discovers several vulnerabilities in the AI ChatBot plugin.
September 28, 2023 – We initiate contact with the plugin developer.
September 29, 2023 – We release a firewall rule to protect Wordfence Premium, Wordfence Care, and Wordfence Response customers and send the full disclosure to the plugin developer. Receipt of the disclosure is acknowledged.
October 10, 2023 – A fixed version (4.9.1) of the plugin that patches all reported vulnerabilities is released.
October 18, 2023 – Several of the vulnerabilities are reintroduced in version 4.9.2. We inform the vendor about this.
October 19, 2023 – Version 4.9.3 patches the vulnerabilities again.
October 29, 2023 – The firewall rule becomes available to free Wordfence users


In this blog post we covered an Unauthenticated SQL Injection vulnerability (affecting versions <= 4.8.9), as well as an Arbitrary File Write vulnerability and an Arbitrary File Deletion vulnerability (affecting versions <= 4.8.9 and 4.9.2). The SQL Injection vulnerability allows unauthenticated attackers to extract sensitive information from the database using a time-based blind injection approach, which could ultimately lead to exposure of admin credentials and site takeover.

The Arbitrary File Write vulnerability can be utilized by authenticated attackers to append opening PHP tags (in default configurations) to any file including the wp-config.php file, which can lead to Denial of Service (DoS). The Arbitrary File Deletion vulnerability can be used by authenticated attackers to delete any file on the web server offering the possibility of complete site takeovers.

All Wordfence running Wordfence Premium, Wordfence Care, and Wordfence Response, have been protected against these vulnerabilities as of September 29, 2023. Users still using the free version of Wordfence will receive the same protection on October 29, 2023.

If you know someone who uses this plugin on their site, we recommend sharing this advisory with them to ensure their site remains secure, as these vulnerabilities pose a significant risk.

For security researchers looking to disclose vulnerabilities responsibly and obtain a CVE ID, you can submit your findings to Wordfence Intelligence and potentially earn a spot on our leaderboard.

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Attacks on 5G Infrastructure From Users’ Devices

By: Salim S.I.
September 20, 2023
Read time: 8 min (2105 words)

Crafted packets from cellular devices such as mobile phones can exploit faulty state machines in the 5G core to attack cellular infrastructure. Smart devices that critical industries such as defense, utilities, and the medical sectors use for their daily operations depend on the speed, efficiency, and productivity brought by 5G. This entry describes CVE-2021-45462 as a potential use case to deploy a denial-of-service (DoS) attack to private 5G networks.

5G unlocks unprecedented applications previously unreachable with conventional wireless connectivity to help enterprises accelerate digital transformation, reduce operational costs, and maximize productivity for the best return on investments. To achieve its goals, 5G relies on key service categories: massive machine-type communications (mMTC), enhanced mobile broadband (eMBB), and ultra-reliable low-latency communication (uRLLC).

With the growing spectrum for commercial use, usage and popularization of private 5G networks are on the rise. The manufacturing, defense, ports, energy, logistics, and mining industries are just some of the earliest adopters of these private networks, especially for companies rapidly leaning on the internet of things (IoT) for digitizing production systems and supply chains. Unlike public grids, the cellular infrastructure equipment in private 5G might be owned and operated by the user-enterprise themselves, system integrators, or by carriers. However, given the growing study and exploration of the use of 5G for the development of various technologies, cybercriminals are also looking into exploiting the threats and risks that can be used to intrude into the systems and networks of both users and organizations via this new communication standard. This entry explores how normal user devices can be abused in relation to 5G’s network infrastructure and use cases.

5G topology

In an end-to-end 5G cellular system, user equipment (aka UE, such as mobile phones and internet-of-things [IoT] devices), connect to a base station via radio waves. The base station is connected to the 5G core through a wired IP network.

Functionally, the 5G core can be split into two: the control plane and the user plane. In the network, the control plane carries the signals and facilitates the traffic based on how it is exchanged from one endpoint to another. Meanwhile, the user plane functions to connect and process the user data that comes over the radio area network (RAN).

The base station sends control signals related to device attachment and establishes the connection to the control plane via NGAP (Next-Generation Application Protocol). The user traffic from devices is sent to the user plane using GTP-U (GPRS tunneling protocol user plane). From the user plane, the data traffic is routed to the external network. 

Figure 1. The basic 5G network infrastructure

The UE subnet and infrastructure network are separate and isolated from each other; user equipment is not allowed to access infrastructure components. This isolation helps protect the 5G core from CT (Cellular Technology) protocol attacks generated from users’ equipment.

Is there a way to get past this isolation and attack the 5G core? The next sections elaborate on the how cybercriminals could abuse components of the 5G infrastructure, particularly the GTP-U.


GTP-U is a tunneling protocol that exists between the base station and 5G user plane using port 2152. The following is the structure of a user data packet encapsulated in GTP-U.

Figure 2. GTP-U data packet

A GTP-U tunnel packet is created by attaching a header to the original data packet. The added header consists of a UDP (User Datagram Protocol) transport header plus a GTP-U specific header. The GTP-U header consists of the following fields:

  • Flags: This contains the version and other information (such as an indication of whether optional header fields are present, among others).
  • Message type: For GTP-U packet carrying user data, the message type is 0xFF.
  • Length: This is the length in bytes of everything that comes after the Tunnel Endpoint Identifier (TEID) field.
  • TEID: Unique value for a tunnel that maps the tunnel to user devices

The GTP-U header is added by the GTP-U nodes (the base station and User Plane Function or UPF). However, the user cannot see the header on the user interface of the device. Therefore, user devices cannot manipulate the header fields.

Although GTP-U is a standard tunneling technique, its use is mostly restricted to CT environments between the base station and the UPF or between UPFs. Assuming the best scenario, the backhaul between the base station and the UPF is encrypted, protected by a firewall, and closed to outside access. Here is a breakdown of the ideal scenario: GSMA recommends IP security (IPsec) between the base station and the UPF. In such a scenario, packets going to the GTP-U nodes come from authorized devices only. If these devices follow specifications and implement them well, none of them will send anomalous packets. Besides, robust systems are expected to have strong sanity checks to handle received anomalies, especially obvious ones such as invalid lengths, types, and extensions, among others.

In reality, however, the scenario could often be different and would require a different analysis altogether. Operators are reluctant to deploy IPsec on the N3 interface because it is CPU-intensive and reduces the throughput of user traffic. Also, since the user data is perceived to be protected at the application layer (with additional protocols such as TLS or Transport Layer Security), some consider IP security redundant. One might think that for as long as the base station and packet-core conform to the specific, there will be no anomalies. Besides, one might also think that for all robust systems require sanity checks to catch any obvious anomalies. However, previous studies have shown that many N3 nodes (such as UPF) around the world, although they should not be, are exposed to the internet. This is shown in the following sections.


Figure 3. Exposed UPF interfaces due to misconfigurations or lack of firewalls; screenshot taken from Shodan and used in a previously published research

We discuss two concepts that can exploit the GTP-U using CVE-2021-45462. In Open5GS, a C-language open-source implementation for 5G Core and Evolved Packet Core (EPC), sending a zero-length, type=255 GTP-U packet from the user device resulted in a denial of service (DoS) of the UPF. This is CVE-2021-45462, a security gap in the packet core that can crash the UPF (in 5G) or Serving Gateway User Plane Function (SGW-U in 4G/LTE) via an anomalous GTP-U packet crafted from the UE and by sending this anomalous GTP-U packet in the GTP-U. Given that the exploit affects a critical component of the infrastructure and cannot be resolved as easily, the vulnerability has received a Medium to High severity rating.

GTP-U nodes: Base station and UPF

GTP-U nodes are endpoints that encapsulate and decapsulate GTP-U packets. The base station is the GTP-U node on the user device side. As the base station receives user data from the UE, it converts the data to IP packets and encapsulates it in the GTP-U tunnel.

The UPF is the GTP-U node on the 5G core (5GC) side. When it receives a GTP-U packet from the base station, the UPF decapsulates the outer GTP-U header and takes out the inner packet. The UPF looks up the destination IP address in a routing table (also maintained by the UPF) without checking the content of the inner packet, after which the packet is sent on its way.


What if a user device crafts an anomalous GTP-U packet and sends it to a packet core?

Figure 4. A specially crafted anomalous GTP-U packet
Figure 5. Sending an anomalous GTP-U packet from the user device

As intended, the base station will tunnel this packet inside its GTP-U tunnel and send to the UPF. This results in a GTP-U in the GTP-U packet arriving at the UPF. There are now two GTP-U packets in the UPF: The outer GTP-U packet header is created by the base station to encapsulate the data packet from the user device. This outer GTP-U packet has 0xFF as its message type and a length of 44. This header is normal. The inner GTP-U header is crafted and sent by the user device as a data packet. Like the outer one, this inner GTP-U has 0xFF as message type, but a length of 0 is not normal.

The source IP address of the inner packet belongs to the user device, while the source IP address of the outer packet belongs to the base station. Both inner and outer packets have the same destination IP address: that of the UPF.

The UPF decapsulates the outer GTP-U and passes the functional checks. The inner GTP-U packet’s destination is again the same UPF. What happens next is implementation-specific:

  • Some implementations maintain a state machine for packet traversal. Improper implementation of the state machine might result in processing this inner GTP-U packet. This packet might have passed the checks phase already since it shares the same packet-context with the outer packet. This leads to having an anomalous packet inside the system, past sanity checks.
  • Since the inner packet’s destination is the IP address of UPF itself, the packet might get sent to the UPF. In this case, the packet is likely to hit the functional checks and therefore becomes less problematic than the previous case.

Attack vector

Some 5G core vendors leverage Open5GS code. For example, NextEPC (4G system, rebranded as Open5GS in 2019 to add 5G, with remaining products from the old brand) has an enterprise offer for LTE/5G, which draws from Open5GS’ code. No attacks or indications of threats in the wild have been observed, but our tests indicate potential risks using the identified scenarios.

The importance of the attack is in the attack vector: the cellular infrastructure attacks from the UE. The exploit only requires a mobile phone (or a computer connected via a cellular dongle) and a few lines of Python code to abuse the opening and mount this class of attack. The GTP-U in GTP-U attacks is a well-known technique, and backhaul IP security and encryption do not prevent this attack. In fact, these security measures might hinder the firewall from inspecting the content.

Remediation and insights

Critical industries such as the medical and utility sectors are just some of the early adopters of private 5G systems, and its breadth and depth of popular use are only expected to grow further. Reliability for continuous, uninterrupted operations is critical for these industries as there are lives and real-world implications at stake. The foundational function of these sectors are the reason that they choose to use a private 5G system over Wi-Fi. It is imperative that private 5G systems offer unfailing connectivity as a successful attack on any 5G infrastructure could bring the entire network down.

In this entry, the abuse of CVE-2021-45462 can result in a DoS attack. The root cause of CVE-2021-45462 (and most GTP-U-in-GTP-U attacks) is the improper error checking and error handling in the packet core. While GTP-U-in-GTP-U itself is harmless, the proper fix for the gap has to come from the packet-core vendor, and infrastructure admins must use the latest versions of the software.

A GTP-U-in-GTP-U attack can also be used to leak sensitive information such as the IP addresses of infrastructure nodes. GTP-U peers should therefore be prepared to handle GTP-U-in-GTP-U packets. In CT environments, they should use an intrusion prevention system (IPS) or firewalls that can understand CT protocols. Since GTP-U is not normal user traffic, especially in private 5G, security teams can prioritize and drop GTP-U-in-GTP-U traffic.

As a general rule, the registration and use of SIM cards must be strictly regulated and managed. An attacker with a stolen SIM card could insert it to an attacker’s device to connect to a network for malicious deployments. Moreover, the responsibility of security might be ambiguous to some in a shared operating model, such as end-devices and the edge of the infrastructure chain owned by the enterprise. Meanwhile, the cellular infrastructure is owned by the integrator or carrier. This presents a hard task for security operation centers (SOCs) to bring relevant information together from different domains and solutions.

In addition, due to the downtime and tests required, updating critical infrastructure software regularly to keep up with vendor’s patches is not easy, nor will it ever be. Virtual patching with IPS or layered firewalls is thus strongly recommended. Fortunately, GTP-in-GTP is rarely used in real-world applications, so it might be safe to completely block all GTP-in-GTP traffic. We recommend using layered security solutions that combine IT and communications technology (CT) security and visibility. Implementing zero-trust solutions, such as Trend Micro™ Mobile Network Security, powered by CTOne, adds another security layer for enterprises and critical industries to prevent the unauthorized use of their respective private networks for a continuous and undisrupted industrial ecosystem, and by ensuring that the SIM is used only from an authorized device. Mobile Network Security also brings CT and IT security into a unified visibility and management console.

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