Microsoft Edge Windows 11 Windows 10 Office for business
Microsoft is always striving to improve and streamline our product experiences—offering a new way to use the classic Microsoft Outlook app on Windows and the Microsoft Edge web browser.
If you have a Microsoft 365 Personal or Family subscription, browser links from the Outlook app will open in Microsoft Edge by default, right alongside the email they’re from in the Microsoft Edge sidebar pane. This allows you to easily access, read, and respond to the message using your matching authenticated profile. No more disruptive switching—just your email and the web content you need to reference, in a single, side-by-side view. And we’re always optimizing the sidebar in Microsoft Edge to give you useful content and tools while you’re browsing so you don’t have to toggle back and forth between windows or even other tabs—whether you’re shopping online or working in a Microsoft 365 web app.
In the future, links from your Microsoft Teams messages will also open in Microsoft Edge by default to help you stay engaged in conversations as you browse the web.
Ultimately though, if this experience isn’t right for you, you can turn off this feature the first time it launches in Microsoft Edge, and then in Outlook settings at any time after that.
FAQ
Why is Microsoft making this change?
To improve your experience between email and browsing—letting you see them both at the same time, in the same place. No more switching back and forth between apps.
To provide a unique experience—at Microsoft, we strive to create the best customer experience across our products.
To reduce task switching and improve workflow and focus—by opening browser links in Microsoft Edge, the original message in Outlook can be viewed alongside web content to easily access, read, and respond to the message, using the matching authenticated profile.
Will this replace my default browser setting in Windows?
No, this only impacts links opened from Microsoft Outlook on Windows and you have the option to turn off this feature in Outlook settings.
I want to open links with the browser set as the default in Windows Settings. How do I do that?
You can choose your preferred browser for opening links from Outlook the first time it launches in Microsoft Edge. After that you can change this setting in Outlook at any time—select File > Options > Advanced > Link handling and choose your preferred browser from the dropdown menu.
In Outlook, go to File.
Select Options.
Select Advanced > Link handling and choose your preferred browser from the dropdown menu.
Will this change affect me if I’m using a Mac?
No, this change will only be applied to Windows 10 and Windows 11 devices.
Send us feedback
Please let us know what you think about the new experience in one of two ways:
In Microsoft Edge, go to Settings and more > Help and feedback > Send feedback. Follow the on-screen instructions and select Send.
Press Alt + Shift + I on your keyboard. Follow the on-screen instructions and select Send.
In this blog entry, we provide technical details and analysis on the 3CX attacks as they happen. We also discuss available solutions which security teams can maximize for early detection and mitigate the impact of 3CX attacks.
By: Trend Micro Research March 30, 2023 Read time: 7 min (1870 words)
Updated on:
April 5, 2:39 a.m. EDT: We added Windows, Mac, and network commands to the Trend Micro Vision One™️ guide in the linked PDF.
April 4, 3:29 a.m. EDT: We added Trend Micro XDR filters to the solutions.
April 3, 2:33 a.m. EDT: We added details on d3dcompiler_47.dll‘s abuse of CVE-2013-3900 to make it appear legitimately signed.
April 1, 1:50 a.m. EDT: We added a guide on how Vision One can be used to search for potential threats associated with the 3CX desktop app.
March 31, 11:07 p.m. EDT: We added technical details, an analysis of the info-stealer payload, and information on Trend Micro XDR capabilities for investigating and mitigating risks associated with the 3CX desktop app.
March 31, 3:00 a.m. EDT: We added the execution flow diagram, a link to Trend Micro support page, and a list of Mac IOCs and detection names.
In late March 2023, security researchers revealed that threat actors abused a popular business communication software from 3CX — in particular, thereports mention that a version of the 3CX VoIP (Voice over Internet Protocol) desktop client was being employed to target 3CX’s customers as part of an attack.
On its forums, 3CX has posted an update that recommends uninstalling the desktop app and using the Progressive Web App (PWA) client instead. The company also mentioned that they are working on an update to the desktop app.
For a more comprehensive scope of protection against possible attacks associated with the 3CX Desktop App, the Trend Micro XDR platform can help organizations mitigate the impact by collecting and analyzing extensive activity data from various sources. By applying XDR analytics to the data gathered from its native products, Trend Micro XDR generates correlated and actionable alerts.
Trend Micro customers can also take advantage of Trend Micro Vision One™ to search for and monitor potential threats associated with the 3CX Desktop App, and to better understand observed attack vectors. For more information on how to utilize Trend Micro Vision One features, you may download the PDF guide here.
Additional guidance for Trend Micro customers including help with protection and detection can be found on our support page.
What is the compromised application?
The 3CX app is a private automatic branch exchange (PABX) software that provides several communication functions for its users, including video conferencing, live chat, and call management. The app is available on most major operating systems, including Windows, macOS, and Linux. Additionally, the client is available as a mobile application for both Android and iOS devices, while a Chrome extension and the PWA version of the client allow users to access the software through their browsers.
The issue was said to be limited to the Electron (non-web versions) of their Windows package (versions 18.12.407 and 18.12.416) and macOS clients (versions 18.11.1213, 18.12.402, 18.12.407 and 18.12.416).
According to the company’s website, more than 600,000 businesses and over 12 million daily users around the world use 3CX’s VoIP IPBX software.
How does the attack work?
The attack is reportedly a multi-stage chain in which the initial step involves a compromised version of the 3CX desktop app. Based on initial analysis, the MSI package (detected by Trend Micro as Trojan.Win64.DEEFFACE.A and Trojan.Win64.DEEFFACE.SMA) is the one that is compromised with possible trojanized DLLs, since the .exe file has the same name.
The infection chain begins with 3CXDesktopApp.exe loading ffmpeg.dll (detected as Trojan.Win64.DEEFFACE.A andTrojan.Win64.DEEFFACE.SMA). Next, ffmpeg.dll reads and decrypts the encrypted code from d3dcompiler_47.dll (detected as Trojan.Win64.DEEFFACE.A and Trojan.Wind64.DEEFACE.SMD3D).
The decrypted code seems to be the backdoor payload that tries to access the IconStorages GiHub page to access an ICO file (detected as Trojan.Win32.DEEFFACE.ICO) containing the encrypted C&C server that the backdoor connects to in order to retrieve the possible final payload. In addition, d3dcompiler_47.dll also abuses CVE-2013-3900 to make it appear that it is legitimately signed.
Figure 1. The detailed execution flow and Trend Micro detections of the malicious files. The MSI installer contains the .exe and two .dll files. The main source of the detection in the MSI installer is “ffmpeg.dll,” which is the trojanized DLL.
As part of its attack routine, it contacts the servers noted in the list of indicators of compromise (IOCs) at the end of this blog entry. These domains are blocked by the Trend Micro Web Reputation Services (WRS).
Execution flow
Upon execution, the MSI package installer will drop the following files that are related to malicious behavior. Trend Micro Smart Scan Pattern (cloud-based) TBL 21474.300.40 can detect these files as Trojan.Win64.DEEFFACE.A.
3CXDesktopApp.exe: A normal file that is abused to load the trojanized DLL
ffmpeg.dll: A trojanized DLL used to read, load, and execute a malicious shellcode from d3dcompiler_47.dll
d3dcompiler_47.dll: A DLL appended with an encrypted shellcode after the fe ed fa ce hex string
Some conditions are necessary for execution. For example, the sleep timestamp varies depending on the following conditions: First, it checks if the manifest file is present, as well as if it is using a specified date. If the file is not present or if it is using the specified date, the timestamp will generate a random number and use the formula rand() % 1800000 + current date + 604800 (604,800 is seven days). After the date is computed, the malware will continue its routine.
Upon execution of 3CXDesktopApp.exe, ffmpeg.dll, which seems to be a trojanized or patched DLL, will be loaded. It will still contain its normal functionalities, but it will have an added malicious function that reads d3dcompiler_47.dll to locate an encrypted shellcode after the fe ed fa ce hex strings.
Figure 2. Reading “d3dcompiler_47.dll” and locating the “fe ed fa ce” hex string
Upon decryption of the malicious shellcode using RC4 with the key, 3jB(2bsG#@c7, the shellcode will then try to access the GitHub repository that houses the ICO files containing the encrypted C&C strings that use Base64 encoding and AES + GCM encryption at the end of the image.
These B64 strings seem to be C&C domains that the shellcode tries to connect to for downloading other possible payloads. However, we were unable to confirm the exact nature of these payloads since the GitHub repository (raw.githubusercontent[.]com/IconStorages/images/main/) had already been taken down at the time of this writing. Note that the process exits when the page is inaccessible.
Figure 3. Code snippet showing the hard-coded GitHub repositoryFigure 4. An ICO file from the GitHub repository
The above description applies to the Windows version. The behaviour of the Mac version is broadly similar, although it only uses a subset of the Windows C&C domains.
Info-stealer payload analysis
Based on our ongoing analysis of attacks on 3CX and the behaviors observed, the following section details what we know so far about the payload’s attack vector.
Payloads in investigated 3CX attacks are detected as TrojanSpy.Win64.ICONICSTEALER.THCCABC. Upon analysis of the payload named ICONIC Stealer, we discovered that if it is executed using regsvr32.exe as the DLL loader, it will display the following system error:
Figure 5. Error displayed upon executing the sample using “regsvr32.exe”
Meanwhile, if rundll32.exe is used as the DLL loader, it encounters a WerFault error and displays the following pop-up message:
Figure 6. Error displayed if “rundll32.exe” is used as the DLL loader
This indicates that the sample must be loaded by a specific application to proceed to its malicious routine.
ICONIC Stealer then checks for a file named config.json under the folder “3CXDesktopApp.”
Figure 7. Checking for “config.json”
ICONIC Stealer was then observed to steal the following system information:
HostName
DomainName
OsVersion
The gathered data will then be converted into a text-string format.
Figure 8. Converting gathered data into a text-string format
ICONIC Stealer then proceeds to its last behavior, which steals browser data. It uses the function shown in Figure 9 to traverse the infected system using predefined directories related to the browser’s history and other browser-related information.
Figure 9. Function for traversing the infected system
The following figure shows a list of predefined strings:
Figure 10. List of predefined strings
The system directories on the following list compose the targets identified in the partial analysis of the ICONIC Stealer’s behavior. More information will be provided as this blog is updated.
AppData\Local\Google\Chrome\User Data
AppData\Local\Microsoft\Edge\User Data
AppData\Local\BraveSoftware\Brave-Browser\User Data
AppData\Roaming\Mozilla\Firefox\Profiles
Browser
Target information
Chrome
History
Edge
History
Brave
History
Firefox
places.sqlite
Table 1. The targeted section of each browser. Note that “places.sqlite” stores the annotations, bookmarks, favorite icons, input history, keywords, and the browsing history of visited pages for Mozilla Firefox.
ICONIC Stealer was also found with the capability to limit the retrieved data to the first five hundred entries to ensure that the most recent browser activity is the data that is retrieved:
Figure 11. Limiting data to the first 500 entries
“UTF-16LE”, ‘SELECT url, title FROM urls ORDER BY id DESC LIMIT
“UTF-16LE”, ‘500’,0
“UTF-16LE”, ‘SELECT url, title FROM moz_places ORDER BY id DESC
“UTF-16LE”, ‘LIMIT 500’,0
Figure 12. Retrieved results stored on an allocated buffer
The gathered data will be passed to the main loader module to POST then back to the C&C server embedded in the main module.
What is its potential impact?
Due to its widespread use and its importance in an organization’s communication system, threat actors can cause major damage (for example, by monitoring or rerouting both internal and external communication) to businesses that use this software.
What can organizations do about it?
Organizations that are potentially affected should stop using the vulnerable version if possible and apply the patches or mitigation workarounds if these are available. IT and security teams should also scan for confirmed compromised binaries and builds and monitor for anomalous behavior in 3CX processes, with a particular focus on C&C traffic.
Meanwhile, enabling behavioral monitoring in security products can help detect the presence of the attack within the system.
The following domains are blocked by Trend Micro Web Reputation Services (WRS)
akamaicontainer[.]com
akamaitechcloudservices[.]com
azuredeploystore[.]com
azureonlinecloud[.]com
azureonlinestorage[.]com
dunamistrd[.]com
glcloudservice[.]com
journalide[.]org
msedgepackageinfo[.]com
msstorageazure[.]com
msstorageboxes[.]com
officeaddons[.]com
officestoragebox[.]com
pbxcloudeservices[.]com
pbxphonenetwork[.]com
pbxsources[.]com
qwepoi123098[.]com
sbmsa[.]wiki
sourceslabs[.]com
visualstudiofactory[.]com
zacharryblogs[.]com
Trend Micro XDR uses the following filters to protect customers from 3CX-related attacks:
Filter
ID
OS
Compromised 3CX Application File Indicators
F6669
macOS, Windows
DLL Sideloading of 3CX Application
F6668
Windows
Web Reputation Services Detection for Compromised 3CX Application
F6670
macOS, Windows
Suspicious Web Access of Possible Compromised 3CX Application
F6673
Windows
Suspicious DNS Query of Possible Compromised 3CX Application
F6672
Windows
Trend Micro Malware Detection Patterns for Endpoint, Servers (Apex One, Worry-Free Business Security Services, Worry-Free Business Security Standard/Advanced, Deep Security with anti-malware, among others), Mail, and Gateway (Cloud App Security, ScanMail for Exchange, IMSVA):
Starting with Trend Micro Smart Scan Pattern (cloud-based) TBL 21474.200.40, known trojanized versions of this application are being detected as Trojan Win64.DEEFFACE.A.
The Mac version of this threat is detected as Trojan.MacOS.FAKE3L3CTRON.A.
The SMTP protocol is the main protocol used to transfer messages between mail servers and is, by default, not secure. The Transport Layer Security (TLS) protocol was introduced years ago to support encrypted transmission of messages over SMTP. It’s commonly used opportunistically rather than as a requirement, leaving much email traffic in clear text, vulnerable to interception by nefarious actors. Furthermore, SMTP determines the IP addresses of destination servers through the public DNS infrastructure, which is susceptible to spoofing and Man-in-the-Middle (MITM) attacks. This vulnerability has led to many new standards being created to increase security for sending and receiving email, one of those standards being DNS-based Authentication of Named Entities (DANE).
DANE for SMTP RFC 7672 uses the presence of a Transport Layer Security Authentication (TLSA) record in a domain’s DNS record set to signal a domain and its mail server(s) support DANE. If there’s no TLSA record present, DNS resolution for mail flow will work as usual without any DANE checks being attempted. The TLSA record securely signals TLS support and publishes the DANE policy for the domain. So, sending mail servers can successfully authenticate legitimate receiving mail servers using SMTP DANE. This authentication makes it resistant to downgrade and MITM attacks. DANE has direct dependencies on DNSSEC, which works by digitally signing records for DNS lookups using public key cryptography. DNSSEC checks occur on recursive DNS resolvers, the DNS servers that make DNS queries for clients. DNSSEC ensures that DNS records aren’t tampered with and are authentic.
Once the MX, A/AAAA and DNSSEC-related resource records for a domain are returned to the DNS recursive resolver as DNSSEC authentic, the sending mail server will ask for the TLSA record corresponding to the MX host entry or entries. If the TLSA record is present and proven authentic using another DNSSEC check, the DNS recursive resolver will return the TLSA record to the sending mail server.
After the authentic TLSA record is received, the sending mail server establishes an SMTP connection to the MX host associated with the authentic TLSA record. The sending mail server will try to set up TLS and compare the server’s TLS certificate with the data in the TLSA record to validate that the destination mail server connected to the sender is the legitimate receiving mail server. The message will be transmitted (using TLS) if authentication succeeds. When authentication fails or if TLS isn’t supported by the destination server, Exchange Online will retry the entire validation process beginning with a DNS query for the same destination domain again after 15 minutes, then 15 minutes after that, then every hour for the next 24 hours. If authentication continues to fail after 24 hours of retrying, the message will expire, and an NDR with error details will be generated and sent to the sender.
Tip
If you’re not an E5 customer, use the 90-day Microsoft Purview solutions trial to explore how additional Purview capabilities can help your organization manage data security and compliance needs. Start now at the Microsoft Purview compliance portal trials hub. Learn details about signing up and trial terms.
What are the components of DANE?
TLSA Resource Record
The TLS Authentication (TLSA) record is used to associate a server’s X.509 certificate or public key value with the domain name that contains the record. TLSA records can only be trusted if DNSSEC is enabled on your domain. If you’re using a DNS provider to host your domain, the DNSSEC may be a setting offered when configuring a domain with them. To learn more about DNSSEC zone signing, visit this link: Overview of DNSSEC | Microsoft Docs.
Example TLSA record:
There are four configurable fields unique to the TLSA record type:
Certificate Usage Field: Specifies how the sending email server should verify the destination email server’s certificate.
Value
Acronym
Description
01
PKIX-TA
Certificate used is the trust-anchor Public CA from the X.509 trust-chain.
11
PKIX-EE
Certificate checked is the destination server; DNSSEC checks must verify its authenticity.
2
DANE-TA
Use server’s private key from the X.509 tree that must be validated by a trust anchor in the chain of trust. The TLSA record specifies the trust anchor to be used for validating the TLS certificates for the domain.
3
DANE-EE
Only match against the destination server’s certificate.
1 Exchange Online follows RFC implementation guidance that Certificate Usage Field values of 0 or 1 shouldn’t be used when DANE is implemented with SMTP. When a TLSA record that has a Certificate Usage field value of 0 or 1 is returned to Exchange Online, Exchange Online will treat it as not usable. If all TLSA records are found unusable, Exchange Online won’t perform the DANE validation steps for 0 or 1 when sending the email. Instead, because of the presence of a TLSA record, Exchange Online will enforce the use of TLS for sending the email, sending the email if the destination email server supports TLS or dropping the email and generating an NDR if the destination email server doesn’t support TLS.
In the example TLSA record, the Certificate Usage Field is set to ‘3’, so the Certificate Association Data (‘abc123…xyz789’) would be matched against the destination server’s certificate only.
Selector field: Indicates which parts of the destination server’s certificate should be checked.
Value
Acronym
Description
0
Cert
Use full certificate.
1
SPKI (Subject Public Key Info)
Use certificate’s public key and the algorithm with which the public key is identified to use.
In the example TLSA record, the Selector Field is set to ‘1’ so the Certificate Association Data would be matched using the destination server certificate’s public key and the algorithm with which the public key is identified to use.
Matching Type Field: Indicates the format the certificate will be represented in the TLSA record.
Value
Acronym
Description
0
Full
The data in the TSLA record is the full certificate or SPKI.
1
SHA-256
The data in the TSLA record is an SHA-256 hash of either the certificate or the SPKI.
2
SHA-512
The data in the TSLA record is an SHA-512 hash of either the certificate or the SPKI.
In the example TLSA record, the Matching Type Field is set to ‘1’ so the Certificate Association Data is an SHA-256 hash of the Subject Public Key Info from the destination server certificate
Certificate Association Data: Specifies the certificate data that is used for matching against the destination server certificate. This data depends on the Selector Field value and the Matching Type Value.
In the example TLSA record, the Certificate Association data is set to ‘abc123..xyz789’. Since the Selector Field value in the example is set to ‘1’, it would reference the destination server certificate’s public key and the algorithm that’s identified to be used with it. And since the Matching Type field value in the example is set to ‘1’, it would reference the SHA-256 hash of the Subject Public Key Info from the destination server certificate.
How can Exchange Online customers use SMTP DANE Outbound?
As an Exchange Online customer, there isn’t anything you need to do to configure this enhanced email security for your outbound email. This enhanced email security is something we have built for you and it’s ON by default for all Exchange Online customers and is used when the destination domain advertises support for DANE. To reap the benefits of sending email with DNSSEC and DANE checks, communicate to your business partners with whom you exchange email that they need to implement DNSSEC and DANE so they can receive email using these standards.
How can Exchange Online customers use SMTP DANE inbound?
Currently, inbound SMTP DANE isn’t supported for Exchange Online. Support for inbound SMTP DANE will be available in the near future.
What is the recommended TLSA record configuration?
Per RFC implementation guidance for SMTP DANE, a TLSA record composed of the Certificate Usage field set to 3, the Selector field set to 1, and the Matching Type field set to 1 is recommended.
Exchange Online Mail Flow with SMTP DANE
The mail flow process for Exchange Online with SMTP DANE, shown in the flow chart below, validates domain and resource record security through DNSSEC, TLS support on the destination mail server, and that the destination mail server’s certificate matches what is expected based on its associated TLSA record.
There are only two scenarios where an SMTP DANE failure will result in the email being blocked:
The destination domain signaled DNSSEC support but one or more records were returned as inauthentic.
All MX records for the destination domain have TLSA records and none of the destination server’s certificates match what was expected per the TSLA record data, or a TLS connection isn’t supported by the destination server.
Related Technologies
Technology
Additional Information
Mail Transfer Agent – Strict Transport Security (MTA-STS) helps thwart downgrade and Man-in-the-Middle attacks by providing a mechanism for setting domain policies that specify whether the destination email server supports TLS and what to do when TLS can’t be negotiated, for example stop the transmission.
More information about Exchange Online’s upcoming support for inbound and outbound MTA-STS will be published later this year.
DomainKeys Identified Mail (DKIM) uses X.509 certificate information to ensure that destination email systems trust messages sent outbound from your custom domain.
Domain-based Message Authentication, Reporting, and Conformance (DMARC) works with Sender Policy Framework and DomainKeys Identified Mail to authenticate mail senders and ensure that destination email systems trust messages sent from your domain.
Currently, there are four error codes for DANE when sending emails with Exchange Online. Microsoft is actively updating this error code list. The errors will be visible in:
The Exchange Admin Center portal through the Message Trace Details view.
NDRs generated when a message isn’t sent due to a DANE or DNSSEC failure.
starttls-not-supported: Destination mail server must support TLS to receive mail.
4/5.7.322
certificate-expired: Destination mail server’s certificate is expired.
4/5.7.323
tlsa-invalid: The domain failed DANE validation.
4/5.7.324
dnssec-invalid: Destination domain returned invalid DNSSEC records.
Note
Currently, when a domain signals that it supports DNSSEC but fails DNSSEC checks, Exchange Online does not generate the 4/5.7.324 dnssec-invalid error. It generates a generic DNS error:
4/5.4.312 DNS query failed
We are actively working to remedy this known limitation. If you receive this error statement, navigate to the Microsoft Remote Connectivity Analyzer and perform the DANE validation test against the domain that generated the 4/5.4.312 error. The results will show if it is a DNSSEC issue or a different DNS issue.
Troubleshooting 4/5.7.321 starttls-not-supported
This error usually indicates an issue with the destination mail server. After receiving the message:
Check that the destination email address was entered correctly.
Alert the destination email administrator that you received this error code so they can determine if the destination server is configured correctly to receive messages using TLS.
Retry sending the email and review the Message Trace Details for the message in the Exchange Admin Center portal.
Troubleshooting 4/5.7.322 certificate-expired
A valid X.509 certificate that hasn’t expired must be presented to the sending email server. X.509 certificates must be renewed after their expiration, commonly annually. After receiving the message:
Alert the destination email administrator that you received this error code and provide the error code string.
Allow time for the destination server certificate to be renewed and the TLSA record to be updated to reference the new certificate. Then, retry sending the email and review the Message Trace Details for the message in the Exchange Admin Center portal.
Troubleshooting 4/5.7.323 tlsa-invalid
This error code is related to a TLSA record misconfiguration and can only be generated after a DNSSEC-authentic TLSA record has been returned. There are many scenarios during the DANE validation that occur after the record has been returned that can result in the code being generated. Microsoft is actively working on the scenarios that are covered by this error code, so that each scenario has a specific code. Currently, one or more of these scenarios could cause the generation of the error code:
The destination mail server’s certificate doesn’t match with what is expected per the authentic TLSA record.
Authentic TLSA record is misconfigured.
The destination domain is being attacked.
Any other DANE failure.
After receiving the message:
Alert the destination email administrator that you received this error code and provide them the error code string.
Allow time for the destination email admin to review their DANE configuration and email server certificate validity. Then, retry sending the email and review the Message Trace Details for the message in the Exchange Admin Center portal.
Troubleshooting 4/5.7.324 dnssec-invalid
This error code is generated when the destination domain indicated it was DNSSEC-authentic but Exchange Online wasn’t able to verify it as DNSSEC-authentic.
After receiving the message:
Alert the destination email administrator that you received this error code and provide them the error code string.
Allow time for the destination email admin to review their domain’s DNSSEC configuration. Then, retry sending the email and review the Message Trace Details for the message in the Exchange Admin Center portal.
Troubleshooting Receiving Emails with SMTP DANE
Currently, there are two methods an admin of a receiving domain can use to validate and troubleshoot their DNSSEC and DANE configuration to receive email from Exchange Online using these standards.
Adopt SMTP TLS-RPT (Transport Layer Security Reporting) introduced in RFC8460
TLS-RPT https://datatracker.ietf.org/doc/html/rfc8460 is a reporting mechanism for senders to provide details to destination domain administrators about DANE and MTA-STS successes and failures with those respective destination domains. To receive TLS-RPT reports, you only need to add a TXT record in your domain’s DNS records that includes the email address or URI you would like the reports to be sent to. Exchange Online will send TLS-RPT reports in JSON format.
Example record:
The second method is to use the Remote Connectivity Analyzer Microsoft Remote Connectivity Analyzer, which can do the same DNSSEC and DANE checks against your DNS configuration that Exchange Online will do when sending email outside the service. This method is the most direct way of troubleshooting errors in your configuration to receive email from Exchange Online using these standards.
When errors are being troubleshooted, the below error codes may be generated:
NDR Code
Description
4/5.7.321
starttls-not-supported: Destination mail server must support TLS to receive mail.
4/5.7.322
certificate-expired: Destination mail server’s certificate has expired.
4/5.7.323
tlsa-invalid: The domain failed DANE validation.
4/5.7.324
dnssec-invalid: Destination domain returned invalid DNSSEC records.
Note
Currently, when a domain signals that it supports DNSSEC but fails DNSSEC checks, Exchange Online does not generate the 4/5.7.324 dnssec-invalid error. It generates a generic DNS error:
4/5.4.312 DNS query failed
We are actively working to remedy this known limitation. If you receive this error statement, navigate to the Microsoft Remote Connectivity Analyzer and perform the DANE validation test against the domain that generated the 4/5.4.312 error. The results will show if it is a DNSSEC issue or a different DNS issue.
Troubleshooting 4/5.7.321 starttls-not-supported
Note
These steps are for email administrators troubleshooting receiving email from Exchange Online using SMTP DANE.
This error usually indicates an issue with the destination mail server. The mail server that the Remote Connectivity Analyzer is testing connecting with. There are generally two scenarios that generate this code:
The destination mail server doesn’t support secure communication at all, and plain, non-encrypted communication must be used.
The destination server is configured improperly and ignores the STARTTLS command.
After receiving the message:
Check the email address.
Locate the IP address that is associated with the error statement so you can identify the mail server the statement is associated with.
Check your mail server’s setting to make sure it’s configured to listen for SMTP traffic (commonly ports 25 and 587).
Wait a few minutes, then retry the test with the Remote Connectivity Analyzer tool.
If it still fails, then try removing the TLSA record and run the test with the Remote Connectivity Analyzer tool again.
If there are no failures, this message may indicate the mail server you’re using to receive mail doesn’t support STARTTLS and you may need to upgrade to one that does in order to use DANE.
Troubleshooting 4/5.7.322 certificate-expired
Note
These steps are for email administrators troubleshooting receiving email from Exchange Online using SMTP DANE.
A valid X.509 certificate that hasn’t expired must be presented to the sending email server. X.509 certificates must be renewed after their expiration, commonly annually. After receiving the message:
Check the IP that is associated with the error statement, so you can identify the mail server it’s associated with. Locate the expired certificate on the email server you identified.
Sign in to your certificate provider’s website.
Select the expired certificate and follow the instructions to renew and to pay for the renewal.
After your provider has verified the purchase, you may download a new certificate.
Install the renewed certificate into its associated mail server.
Update the mail server’s associated TLSA record with the new certificate’s data.
After waiting an appropriate amount of time, retry the test with the Remote Connectivity Analyzer tool.
Troubleshooting 4/5.7.323 tlsa-invalid
Note
These steps are for email administrators troubleshooting receiving email from Exchange Online using SMTP DANE.
This error code is related to a TLSA record misconfiguration and can only be generated after a DNSSEC-authentic TSLA record has been returned. But, there are many scenarios during the DANE validation that occur after the record has been returned that can result in the code being generated. Microsoft is actively working on the scenarios that are covered by this error code, so that each scenario has a specific code. Currently, one or more of these scenarios could cause the generation of the error code:
Authentic TLSA record is misconfigured.
The certificate isn’t yet time valid/configured for a future time window.
Destination domain is being attacked.
Any other DANE failure.
After receiving the message:
Check the IP that is associated with the error statement to identify the mail server it’s associated with.
Identify the TLSA record that is associated with the identified mail server.
Verify the configuration of the TLSA record to ensure that it signals the sender to perform the preferred DANE checks and that the correct certificate data has been included in the TLSA record.
If you have to make any updates to the record for discrepancies, then wait a few minutes then rerun the test with the Remote Connectivity Analyzer tool.
Locate the certificate on the identified mail server.
Check the time window for which the certificate is valid. If it’s set to start validity at a future date, it needs to be renewed for the current date.
Sign in to your certificate provider’s website.
Select the expired certificate and follow the instructions to renew and to pay for the renewal.
After your provider has verified the purchase, you may download a new certificate.
Install the renewed certificate into its associated mail server.
Troubleshooting 4/5.7.324 dnssec-invalid
Note
These steps are for email administrators troubleshooting receiving email from Exchange Online using SMTP DANE.
This error code is generated when the destination domain indicated it’s DNSSEC-authentic but Exchange Online isn’t able to verify it as DNSSEC-authentic. This section won’t be comprehensive for troubleshooting DNSSEC issues and focuses on scenarios where domains previously passed DNSSEC authentication but not now.
After receiving the message:
If you’re using a DNS provider, for example GoDaddy, alert your DNS provider of the error so they can work on the troubleshooting and configuration change.
If you’re managing your own DNSSEC infrastructure, there are many DNSSEC misconfigurations that may generate this error message. Some common problems to check for if your zone was previously passing DNSSEC authentication:
Broken trust chain, when the parent zone holds a set of DS records that point to something that doesn’t exist in the child zone. Such pointers by DS records can result in the child zone being marked as bogus by validating resolvers.
Resolve by reviewing the child domains RRSIG key IDs and ensuring that they match with the key IDs in the DS records published in the parent zone.
RRSIG resource record for the domain isn’t time valid, it has either expired or its validity period hasn’t begun.
Resolve by generating new signatures for the domain using valid timespans.
Note
This error code is also generated if Exchange Online receives SERVFAIL response from DNS server on TLSA query for the destination domain.
When an outbound email is being sent, if the receiving domain has DNSSEC enabled, we query for TLSA records associated with MX entries in the domain. If no TLSA record is published, the response to the TLSA lookup must be NOERROR (no records of requested type for this domain) or NXDOMAIN (there’s no such domain). DNSSEC requires this response if no TLSA record is published; otherwise, Exchange Online interprets the lack of response as a SERVFAIL error. As per RFC 7672, a SERVFAIL response is untrustworthy; so, the destination domain fails DNSSEC validation. This email is then deferred with the following error:
450 4.7.324 dnssec-invalid: Destination domain returned invalid DNSSEC records
If the email sender reports receipt of the message
If you’re using a DNS provider, for example, GoDaddy, alert your DNS provider of the error so that they can troubleshoot the DNS response. If you’re managing your own DNSSEC infrastructure, it could be an issue with the DNS server itself or with the network.
Frequently Asked Questions
As an Exchange Online customer, can I opt out of using DNSSEC and/or DANE?
We strongly believe DNSSEC and DANE will significantly increase the security position of our service and benefit all of our customers. We’ve worked diligently over the last year to reduce the risk and severity of the potential impact this deployment might have for Microsoft 365 customers. We’ll be actively monitoring and tracking the deployment to ensure negative impact is minimized as it rolls out. Because of this, tenant-level exceptions or opt-out won’t be available. If you experience any issues related to the enablement of DNSSEC and/or DANE, the different methods for investigating failures noted in this document will help you identify the source of the error. In most cases, the issue will be with the external destination party and you’ll need to communicate to these business partners that they need to correctly configure DNSSEC and DANE in order to receive email from Exchange Online using these standards.
How does DNSSEC relate to DANE?
DNSSEC adds a layer of trust into DNS resolution by applying the public key infrastructure to ensure the records returned in response to a DNS query are authentic. DANE ensures that the receiving mail server is the legitimate and expected mail server for the authentic MX record.
What is the difference between MTA-STS and DANE for SMTP?
DANE and MTA-STS serve the same purpose, but DANE requires DNSSEC for DNS authentication while MTA-STS relies on certificate authorities.
Why isn’t Opportunistic TLS sufficient?
Opportunistic TLS will encrypt communication between two endpoints if both agree to support it. However, even if TLS encrypts the transmission, a domain could be spoofed during DNS resolution such that it points to a malicious actor’s endpoint instead of the real endpoint for the domain. This spoof is a gap in email security that is addressed by implementing MTA-STS and/or SMTP DANE with DNSSEC.
Why isn’t DNSSEC sufficient?
DNSSEC isn’t fully resistant to Man-in-the-Middle attacks and downgrade (from TLS to clear text) attacks for mail flow scenarios. The addition of MTA-STS and DANE along with DNSSEC provides a comprehensive security method to thwart both MITM and downgrade attacks.
This is a Friday long-read, so grab a warm cup of something and kick back because we’re going to take our time on this. The world is about to profoundly change. I know you’re nervous – perhaps excited and optimistic, but if you’ve been paying attention and have been watching the trajectory of this thing, the rational reaction is to be nervous. In this post I’d like to unpack in practical and tangible terms what AI is, where it came from, and the state of play, and then I’ll show you a path that will give you a pretty good shot at surviving the coming revolution.
Who am I? I’m Mark Maunder and I founded Wordfence in 2011 and wrote the early versions of the product until 2015 when Matt Barry took over as lead developer and I morphed into a tech executive running Defiant Inc, which makes Wordfence. We have over 4 million customers using our free product and a large number of paying customers using our various paid WordPress security products. I’ve been a technologist since the early 90s and a kid hacker in my teens in the 80s and 90s. I started my career in mission-critical operations for companies like Coca-Cola, Credit Suisse (now UBS), and DeBeers and then went over to do dev for companies like the BBC and eToys which was one of the biggest dot-com busts. I created the first job meta-search called WorkZoo in the UK around 2001 which later competed with Indeed, launched after us, and which I sold in 2005 but which made Time Magazine and NYTimes. I subsequently launched a Geoblogging platform, inline comments via JS, an ad network, real-time analytics, a localized news website, and more. You could say I’ve been in the innovation game for a minute, and I’m in it for life. I’m based in the USA these days in case you’re curious – moved over here in 2003.
Examining Bubbles
My apologies for the long bio, but what I’d like to illustrate is that I’ve seen tech come and go. The hype cycles I’ve seen typically include:
Outlandish claims about how the tech will solve everything from slicing bread to world peace and everything in between.
Commercial vendors jumping on the emerging mega-trend to surf the wave with proprietary technologies of their own which they position as standards, or at the very least the default choice.
Nascent technologies implementing the tech, that are immature, unstable, rapidly changing, and may very well be abandoned in a few months or a few years.
The press contracting a bad case of rabies and foaming at the mouth about the tech, amplifying the most extreme aspects and use cases and creating a lot of noise, which makes it hard for implementors to sift for the truth and the fundamentals around the technology.
The investment community pouring cash into the space with little focus. This creates an extremely adversarial environment for tech practitioners who are building fundamental value, who now have to compete with powerful VC-backed marketing machines.
As Warren Buffet says, the Innovators, the Imitators, and the Swarming Incompetents enter the space in that order. I’d add that they have a pyramid structure with each successive wave being at least an order of magnitude bigger than the last. Things get crowded for a while.
Then you have the typical bust cycle which cleans house and makes the tech uncool again, but also makes it interesting to the true believers. The VC’s go away and stop making noise that innovators have to compete against. The imitators and swarming incompetents drift off to imitate and mess up something else. The businesses not creating fundamental value fail. Some creating fundamental value fail too but the talent and tech are sometimes reincarnated into something else useful.
So who prospers, and what tech survives after a bust? Sometimes none of it, but helpful derivative technologies are created, like Java Applets in the 90s that inspired Flash which inspired standards-based rich content web browsers.
Sometimes out of the ashes, an Amazon is born, as with the dot-com boom. And sometimes you have incredible innovation where the innovators never see large-scale commercial success, but others do, as with Igor Sysoyev who created Nginx which eliminated the need for a data center full of web servers to handle large-scale websites. Igor has a commercial thing, but the real winners were companies like Cloudflare who based their global infrastructure on Nginx, reverse proxying massive numbers of connections to origin servers with rules about what gets proxied. Hey, I benefited too. Nginx saved our behinds when Kerry and I were running Feedjit.com from 2007 to 2011 because it let us handle over 1 billion application requests per month on just 6 servers. Thanks Igor!
Blockchain technology is in a bust cycle and you can map the characteristics I defined above to blockchain. It looks eerily similar to the dot-com bust and you’ll see an Amazon emerge from the ashes about a decade from now. It might be Coinbase if they survive the over 80% dive in market cap that may continue, but who knows?
Derivative Versus Fundamental Technology Innovation
I’ve mentioned a few tech bubbles so far and it’s really the first step in pulling us out of the trees so that we can examine the various forests out there. Now let’s go a little more meta and talk about which forests matter. Some technology is derivative. Examples of derivative tech are new stuff that runs inside a browser, for example, Websockets.
Websockets are awesome because they let a browser keep a connection open and get push notifications without doing the old TCP three-way handshake to establish a new connection every time the browser wants to check if there’s data waiting on a chat server or whatever. We used to call this long-polling and I wrote a web server to do long polling which was a clumsy but necessary approach, so when Web Sockets came along we all breathed a sigh of relief and I happily retired my web server glad that no one would see my nasty source code which worked quite well mind you.
Another derivative technology – and you’re not going to like this – is blockchain. It’s a useful and novel implementation of hashing algorithms and a few other cryptographic tricks, but honestly, we should have disintermediated banking at least two decades ago and the fact that blockchain has still failed to do that is both disappointing and illustrative that it is just a set of derivative applications built on a tower of fundamentals that has a way to go before it matures. The hype cycle and speculative bubble around it was simply humans making human noise.
So that’s derivative tech. In addition to derivative tech, you have what I’d like to call fundamental tech. Electricity is fundamental. It’s cornerstone technology that transformed the world in our ability to use and transport energy which has enabled an industrial and technological revolution the likes of which the world has never seen. The microprocessor is also fundamental tech for similar reasons. You have algorithms that are fundamental tech like the RSA algorithm which allows us to establish a secure communication channel while a bad person is listening in the whole time – the kind of tech that could have changed the outcome of World War II.
The Internet is fundamental tech. It connected the world and gave us the ability to build applications on top like HTTP and the web which are derivative tech.
Oh I know you want to have a bar fight with me at this point and we’ll do that if you’re attending Wordcamp EU – a collegial and metaphorical barfight, that is – but hopefully, you’re picking up what I’m putting down here in a general sense: There is fundamental tech that profoundly enables and changes the world and which many other things are built on top of, and there is derivative tech that gets a lot of attention but isn’t quite as transformative in a historical sense if you’re thinking in terms of centuries. And there’s the big fat grey area in between.
AI is fundamental tech. For decades we have been programming by writing functions by hand. We’ve gotten quite good at structuring our code using metaphors like object-oriented programming to create logical structures that make sense in a human world, and help us organize large code bases. But fundamentally the way we define logic in a program hasn’t changed for a long time. Until now. For the first time in all of history, we can create functions in programming by training them, rather than writing them by hand. In other, slightly more technical words, we can infer a function from observations and then use it. Like babies and toddlers do. This is historic, it’s transformative and it is a fundamental breakthrough.
Funny thing is that until quite recently – around 2015 – AI had suffered many so-called “AI Winters” where there was significant interest in the field that catalyzed investment dollars, and then a setback usually caused by a reality check, that caused a winter in funding and interest. Does anyone remember the “expert systems” of the 80s? By the early 2000s AIs name had been dragged through the mud so many times that anyone doing serious research in the field used different words to describe their work, like “machine learning” or “informatics” or “knowledge systems”.
A few hardcore true believers like Yann Lecun, Yushua Bengio and Geoffrey Hinton powered through like Bilbo and Sam across The Dead Marshes and went on to win the Turing Award, which is basically the Nobel Prize of computer science and which I had the privilege of attending when Rivest, Adleman and Shamir won theirs for public key crypto. The Turing Award is a very big deal and well deserved considering how adversarial the AI environment was for a while.
So what changed? Well for one thing you’re reading this post because it’s about AI and you’re interested. And you’re interested because you recently used GPT-4, MidJourney, Dall-E or another model to create something. You’re seeing tangible results. And the reason you’re seeing results is that GPU hardware, algorithms, and an interest in the field have brought us to an inflection point where the technology is delivering results that are jaw-dropping enough to catalyze more funding, more research, and more jaw-dropping results. This cycle really picked up steam in 2015, and with the release of GPT-4 recently, has entered a phase of what I would describe as true and consistent exponential growth.
According to NVidia “LLM sizes have been increasing 10X every year for the last few years”. In two years that’s 100X. Three years from now that’s 1000X and so on. Extrapolate that out and be afraid. Or optimistic if your mind isn’t for rent and you are hopeful yet discontent. Rush lyrics aside, that pace should give you an idea of how quickly this thing is coming. And now that we’ve reached the point of inflection I mentioned, where the hardware and algorithms seem to have overcome the cycle of disappointment that AI has been stuck in for decades, I predict that you’ll see consistent and exponential growth in the field in capabilities for the foreseeable future, with a financial bubble and bust in there that won’t be of much consequence to the fundamental value of the technology.
“Thanks for the history lesson Maunder, but you brought us here with promises of telling us what to do about AI. So?”
What to do about AI
So far we’ve discussed what boom cycles look like and the kind of noise and bear traps you should be aware of. We’ve defined what AI is in fundamental terms – a function that you can train rather than hand code. And we’ve hopefully agreed that we’ve entered a period of consistent and exponential growth in the field. Now we’ll chat about how to survive and prosper in a world that looks a lot like when electricity was invented and commercialized, or the microprocessor, or the Internet.
Goldman estimates that AI will add 7% to global GDP at a rate of about 1.5% growth per year. They also estimate that roughly two-thirds of US occupations are exposed to some degree of automation by AI. You can extrapolate this globally. That kind of global disruption is matched only by the industrial revolution or the entire recent tech revolution as a whole starting from 1980. From the same publication, “A recent study by economist David Autor cited in the report found that 60% of today’s workers are employed in occupations that didn’t exist in 1940.”. So on an optimistic note, this kind of disruption isn’t a new thing and we’ve been disrupting and adapting for some time now.
Perhaps you’re reading this because you are running a WordPress website, perhaps secured by my product, Wordfence. Which means you’re a creator of some kind. Perhaps you’re a writer, an artist, or perhaps you’re an entrepreneur creating a business out of thin air. [Yes my fellow entreps, you get to hang with the other cool creator kids too!!]. If you don’t plan on adapting at all, that makes you far more vulnerable to this coming wave than say a chef who runs a restaurant, or someone who manages real estate and rentals. And that really is the key: adaptation. So how can we adapt?
If you’re a creator, you need to become a user of AI. You’re probably already using GPT to write copy for your product catalogs on your e-commerce website, or using MidJourney (MJ) or Dall-E to create art for ad campaigns. If you’re a designer or artist, you may feel the kind of resentment this Blender artist does in the Blender subreddit.
“My Job is different now since Midjourney v5 came out last week. I am not an artist anymore, nor a 3D artist. Rn all I do is prompting, photoshopping and implementing good looking pictures. The reason I went to be a 3D artist in the first place is gone. I wanted to create form In 3D space, sculpt, create. With my own creativity. With my own hands.”
“It came over night for me. I had no choice. And my boss also had no choice. I am now able to create, rig and animate a character thats spit out from MJ in 2-3 days. Before, it took us several weeks in 3D. The difference is: I care, he does not. For my boss its just a huge time/money saver.”
While I sympathize with how hard change and disruption can be, it’s been a constant for the past couple of centuries in many fields. MidJourney has a long way to go before it can match a real-world artist, unless you’re just churning out images and letting the AI guide the design choices and are happy to work around the bugs. For MidJourney and other generative AIs to produce exactly what we want, they’re going to have to get better at understanding what exactly we want to create. And that’s where the skill comes in. You’re already seeing this with a document that someone has created listing famous photographers and examples of their look. This can be used in MJ prompts to say “in the style of” to get a specific look, but it is an incredibly rudimentary approach.
Another way to guide the MJ AI in particular is to blend photos it has generated. Again, super rudimentary, but it’s the start of having the ability to tightly specify exactly what you want and get that out of MJ. And if you need a reminder of how basic it still is, try to get MJ to generate hands. It still sucks, even at version 5.
So if you’re a creator, start getting good at using the tools now, understand their limitations, and evolve as the products evolve until you’re an expert at guiding the AI to create exactly what you want. This will help you guide your customers in explaining the limits of the current state of AI to them and where you add value, let you take immediate advantage of the use that the current tools have, and ramp up your productivity as the tools get better at taking instructions from you.
This applies to writers, artists, designers, filmmakers, photographers, screenwriters, and anyone with creative output. Get good at the tools. Get good at them now. Do it with an open mind. Know that changes aren’t permanent and that change is. (Again with sneaking in the Rush lyrics)
Adapting as a Dev
Coders! My people! We have a problem. Most of you have become users of AI. You’re users of GPT-4 via their API. You’re plugging into other generative AIs via an API. You aren’t rolling your own. And rolling your own is where all the fun is!!
Ever heard of transfer learning? You can grab a pre-trained model from Hugging Face, chop off the head – aka the final layer in the layers of neural nets, substitute it with random weights, and train the pre-trained model with your own data to take advantage of the sometimes millions of dollars that someone else already spent training their model. In fact Facebook’s LLAMA model which is one of the largest LLM’s in the world was leaked via Torrent recently.
The most important thing you need to do right now as a developer is to stop being a user of AI and become a dev of AI. GPT-4 is a shiny ball that the world will have forgotten about in a year, but it’s a very shiny and attractive ball right now that is fueling many a late-night dev chat. Remember that stat I gave you above? That LLM’s have been increasing in size at 10X per year. The current state of the art will be accessible to you on a desktop in a few years and you need to get ready for that world today.
I’m going to just go ahead and tell you what you need to do to get your AI stuff together, fast.
Ignore the math. Trust me on this. Most people including devs are not good at math and it intimidates the hell out of them. AI is just matrix multiplication and addition using GPU cores to parallelize the ops. Expressing this as code is easy. Expressing it as math will make you hide under your bed and cry. Ignore the math. If you can code, you’ll get it.
Learn Python. Everything in AI is Python. It’s a beautiful little language that you’ll come to appreciate very quickly if you’re already a dev. It’s like coming over to Aikido if you’re already a black belt. OK the MMA scene kinda messed up my metaphor proving that Aikido is actually worthless, but whatever.
Then go do the Practical Deep Learning for Coders course at fast.ai. It’s how we get our guys up to speed fast in the field and it’s brilliant. Jeremy Howard does a spectacular job of getting you up to speed fast in the field by immediately getting you productive and then unpacking the details in a fun non-mathy way.
As you progress in the course, definitely get up to speed using Jupyter Notebooks and I’d recommend Kaggle for this. They were bought by Google a few years ago and kind of compete with Google’s own notebook system called Colab, but I prefer Kaggle. You get GPU access by simply verifying your email address and it’s free which is kind of amazing. So you can use a rich text environment on Kaggle to write your code, see the output and run it on some fairly decent GPUs. Kaggle GPU’s perform at about 20% of the speed of my laptop RTX 4090 in case you’re curious about benchmarks.
The course teaches fundamentals, how to use pre-trained models, how to create Jupyter Notebooks or fork others, how to create Hugging Face Spaces, and how to share your models and their output with the world. It is the fastest way right now to transform yourself from an AI user into an AI dev and get drinks bought for you at parties by folks that have not yet made the leap.
Alright, this went long but that was the plan. We’ll talk more about AI. Go forth, be brave, learn, and create!
Mark Maunder – Founder & CEO – Wordfence and Defiant Inc.
Footnotes: All images on the page were created with MidJourney and if you’d like to see the prompt I used, simply view the image in a new tab and the image name is the prompt, all except for the heavy metal hands image which a colleague created. I’ll be in the comments in case there’s discussion.
Note: Content from this post first appeared in r/CrowdStrike
We will continue to update on this dynamic situation as more details become available. CrowdStrike’s Intelligence team is in contact with 3CX.
On March 29, 2023, CrowdStrike observed unexpected malicious activity emanating from a legitimate, signed binary, 3CXDesktopApp — a softphone application from 3CX. The malicious activity includes beaconing to actor-controlled infrastructure, deployment of second-stage payloads, and, in a small number of cases, hands-on-keyboard activity.
The CrowdStrike Falcon® platform has behavioral preventions and atomic indicator detections targeting the abuse of 3CXDesktopApp. In addition, CrowdStrike® Falcon OverWatch™ helps customers stay vigilant against hands-on-keyboard activity.
The 3CXDesktopApp is available for Windows, macOS, Linux and mobile. At this time, activity has been observed on both Windows and macOS.
CrowdStrike Intelligence has assessed there is suspected nation-state involvement by the threat actor LABYRINTH CHOLLIMA. CrowdStrike Intelligence customers received an alert this morning on this active intrusion.
The CrowdStrike Falcon platform protects customers from this attack and has coverage utilizing behavior-based indicators of attack (IOAs) and indicators of compromise (IOCs) based detections targeting malicious behaviors associated with 3CX on both macOS and Windows.
Customers should ensure that prevention policies are properly configured with Suspicious Processes enabled.
Figure 1. CrowdStrike’s indicator of attack (IOA) identifies and blocks the malicious behavior in macOS (click to enlarge)
Figure 2. CrowdStrike’s indicator of attack (IOA) identifies and blocks the malicious behavior in Windows (click to enlarge)
Hunting in the CrowdStrike Falcon Platform
Falcon Discover
CrowdStrike Falcon® Discover customers can use the following link: US-1 | US-2 | EU | Gov to look for the presence of 3CXDesktopApp in their environment.
Falcon Insight customers can assess if the 3CXDesktopApp is running in their environment with the following query:
Event Search — Application Search
event_simpleName IN (PeVersionInfo, ProcessRollup2) FileName IN ("3CXDesktopApp.exe", "3CX Desktop App")
| stats dc(aid) as endpointCount by event_platform, FileName, SHA256HashData
Falcon Long Term Repository — Application Search
#event_simpleName=/^(PeVersionInfo|ProcessRollup2)$/ AND (event_platform=Win ImageFileName=/\\3CXDesktopApp\.exe$/i) OR (event_platform=Mac ImageFileName=/\/3CX\sDesktop\sApp/i)
| ImageFileName = /.+(\\|\/)(?.+)$/i
| groupBy([event_platform, FileName, SHA256HashData], function=count(aid, distinct=true, as=endpointCount))
Atomic Indicators
The following domains have been observed beaconing, which should be considered an indication of malicious intent.
CrowdStrike Falcon® Insight customers, regardless of retention period, can search for the presence of these domains in their environment spanning back one year using Indicator Graph: US-1 | US-2 | EU | Gov.
Event Search — Domain Search
event_simpleName=DnsRequest DomainName IN (akamaicontainer.com, akamaitechcloudservices.com, azuredeploystore.com, azureonlinecloud.com, azureonlinestorage.com, dunamistrd.com, glcloudservice.com, journalide.org, msedgepackageinfo.com, msstorageazure.com, msstorageboxes.com, officeaddons.com, officestoragebox.com, pbxcloudeservices.com, pbxphonenetwork.com, pbxsources.com, qwepoi123098.com, sbmsa.wiki, sourceslabs.com, visualstudiofactory.com, zacharryblogs.com)
| stats dc(aid) as endpointCount, earliest(ContextTimeStamp_decimal) as firstSeen, latest(ContextTimeStamp_decimal) as lastSeen by DomainName
| convert ctime(firstSeen) ctime(lastSeen)
We break down the basic information of CVE-2023-23397, the zero-day, zero-touch vulnerability that was rated 9.8 on the Common Vulnerability Scoring System (CVSS) scale.
Update as of 03/22/3023 2:50PM PHT: Updated the prevention and mitigation section for an additional step.
CVE-2023-23397 is a critical privilege elevation/authentication bypass vulnerability in Outlook, released as part of the March Patch Tuesday set of fixes. The vulnerability, which affects all versions of Windows Outlook, was given a 9.8 CVSS rating and is one of two zero-day exploits disclosed on March 14. We summarize the points that security teams need to know about this vulnerability and how they can mitigate the risks of this gap.
What is it?
CVE-2023-23397 is an elevation of privilege (EoP) vulnerability in Microsoft Outlook. It is a zero-touch exploit, meaning the security gap requires low complexity to abuse and requires no user interaction.
Figure 1. General exploitation routine of CVE-2023-23397
How is CVE-2023-23397 exploited?
The attacker sends a message to the victim with an extended Message Application Program Interface (MAPI) property with a Universal Naming Convention (UNC) path to a remote attacker-controlled Server Message Block (SMB, via TCP 445). Share-hosted on a server controlled by the attacker, the vulnerability is exploited whether the recipient has seen the message or not. The attacker remotely sends a malicious calendar invite represented by .msg — the message format that supports reminders in Outlook — to trigger the vulnerable API endpoint PlayReminderSound using “PidLidReminderFileParameter” (the custom alert sound option for reminders).
When the victim connects to the attacker’s SMB server, the connection to the remote server sends the user’s New Technology LAN Manager (NTLM) negotiation message automatically, which the attacker can use for authentication against other systems that support NTLM authentication.
NTLMv2 hashes are the latest protocol Windows uses for authentication, and it is used for a number of services with each response containing a hashed representation of users’ information, such as the username and password. As such, threat actors can attempt a NTLM relay attack to gain access to other services, or a full compromise of domains if the compromised users are admins. While online services such as Microsoft 365 are not susceptible to this attack because they do not support NTLM authentication, the Microsoft 365 Windows Outlook app is still vulnerable.
How easy is it to exploit?
User interaction is not necessary to trigger (even before message preview) it, nor does it require high privileges. CVE-2023-23397 is a zero-touch vulnerability that is triggered when the victim client is prompted and notified (e.g., when an appointment or task prompts five minutes before the designated time). It is difficult to block outbound SMB traffic for remote users. The attacker could use the same credentials to gain access to other resources. We elaborate on this example in our webinar (at 04:23 of the video).
Is it in the wild? What versions and operating systems (OS) are affected?
There have been reports of limited attacks abusing this gap. Microsoft has been coordinating with the affected victims to remediate this concern. All supported versions of Microsoft Outlook for Windows are affected. Other versions of Microsoft Outlook, such as Android, iOS, Mac, as well as Outlook on the web and other M365 services, are not affected.
What are the possible attack scenarios?
Figure 2. Beyond the exploit use scenario 1: Data and information theft via NTLM relay attack
1. Lateral movement, malicious navigation using the relayed NTLM hashes
Relay attacks gained notoriety as a use case for Mimikatz using the NTLM credential dumping routine via the sekurlsa module. In addition, pass-the-hat (PtH) (or pass-the hash) attacks and variations of data and information theft can be done. Once attackers are in the system, they can use the network for lateral movement and navigate the organization’s lines over SMB.
Figure 3. Beyond the exploit use scenario 2: WebDAV directory traversal for remote code execution (RCE)
2. WebDAV directory traversal for payload attacker routines
It’s possible for an attacker to leverage WebDAV services in cases where no valid SMB service for Outlook exists (i.e., is not configured) in the client. This is an alternative to the Web/HTTP service that can also be read as a UNC path by .msg and/or Outlook Calendar items. Attackers can set up a malicious WebDAV server to respond to affected victim clients with malicious pages. These pages may contain code that can range from leveraging a directory traversal technique similar to the Microsoft vulnerability CVE-2022-34713 (dubbed as DogWalk) to push any form of payload for remote code execution such as webshells.
What can I do to prevent and mitigate the risk of exploitation of CVE-2023-23397?
Here are some steps that security administrators can perform to reduce the risk of exploitation of CVE-2023-23397:
Apply the vendor patches immediately. Microsoft has released a patch as part of their March 2023 Monthly Security Update.
Block TCP 445/SMB outbound from your network. This will prevent the sending of NTLM authentication messages to remote file shares. If this cannot be done, we recommend monitoring outbound traffic over port 445 for unknown external IP addresses, then identifying and blocking them.
Customers can disable the WebClient service. Note that this will block all WebDAV connections, including intranet.
Add users to the Protected Users Security Group. This prevents the use of NTLM as an authentication mechanism, but note that this could impact applications that rely on NTLM in your environment.
Enforce SMB signing on clients and servers to prevent a relay attack.
Microsoft has provided a PowerShell script as a solution to the issue. The script is designed to scan emails, calendar entries, and task items, and to verify if they have the “PidLidReminderFileParameter” property. By running the script, administrators can locate problematic items that have this property and subsequently remove them or delete them permanently. Download the script here: https://github.com/microsoft/CSS-Exchange/blob/a4c096e8b6e6eddeba2f42910f165681ed64adf7/docs/Security/CVE-2023-23397.md.
Which Trend Micro solutions can address this vulnerability?
Trend Micro Malware Detection Patterns (VSAPI, Predictive Learning, Behavioral Monitoring and Web Reputation Service) for Endpoint, Servers, Mail, and Gateway (e.g., Apex One, Worry-Free Business Security Services, Worry-Free Business Security Standard/Advanced, Deep Security with anti-malware, etc.):
Starting with Trend Micro Smart Scan Pattern version 21474.296.07, known exploits associated with this vulnerability are being detected as Trojan.Win32.CVE202323397.
Trend Micro Vision One: Use this solution as an investigation tool. In the “Search App,” select “Endpoint Activity Data” and enter the following query: – dpt: 445 AND eventSubId: 204 AND processCmd: *OUTLOOK*. This can be saved and added to a watchlist if desired.
Cloud One Workload Security and Deep Security: IPS Rule 1009058, which will need to be changed to Prevent.
TippingPoint Filters:
28471 SMB: SMBv1 Successful Protocol Negotiation
28472 SMB: SMBv2 Successful Protocol Negotiation
Please note: Enabling these filters in Block mode will interrupt legitimate SMB traffic. Customers are advised to add exceptions for their Private IP address space.
If NTLM v1 is configured by default, customers can use this rule to monitor attempts for outgoing NTLM handshakes. Please note this rule only detects and does not block, so it is best used as an investigative tool for follow-up.
Use these steps when a Remote Desktop client can’t connect to a remote desktop but doesn’t provide messages or other symptoms that would help identify the cause.
Check the status of the RDP protocol
Check the status of the RDP protocol on a local computer
Check the status of the RDP protocol on a remote computer
Important
Follow this section’s instructions carefully. Serious problems can occur if the registry is modified incorrectly. Before you start modifying the registry, back up the registry so you can restore it in case something goes wrong.
To check and change the status of the RDP protocol on a remote computer, use a network registry connection:
First, go to the Start menu, then select Run. In the text box that appears, enter regedt32.
In the Registry Editor, select File, then select Connect Network Registry.
In the Select Computer dialog box, enter the name of the remote computer, select Check Names, and then select OK.
Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server and to HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services.
If the value of the fDenyTSConnections key is 0, then RDP is enabled.
If the value of the fDenyTSConnections key is 1, then RDP is disabled.
To enable RDP, change the value of fDenyTSConnections from 1 to 0.
Check whether a Group Policy Object (GPO) is blocking RDP on a local computer
If you can’t turn on RDP in the user interface or the value of fDenyTSConnections reverts to 1 after you’ve changed it, a GPO may be overriding the computer-level settings.
To check the group policy configuration on a local computer, open a Command Prompt window as an administrator, and enter the following command:
Windows Command PromptCopy
gpresult /H c:\gpresult.html
After this command finishes, open gpresult.html. In Computer Configuration\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Session Host\Connections, find the Allow users to connect remotely by using Remote Desktop Services policy.
If the setting for this policy is Enabled, Group Policy is not blocking RDP connections.
If the setting for this policy is Disabled, check Winning GPO. This is the GPO that is blocking RDP connections.
Check whether a GPO is blocking RDP on a remote computer
To check the Group Policy configuration on a remote computer, the command is almost the same as for a local computer:
The file that this command produces (gpresult-<computer name>.html) uses the same information format as the local computer version (gpresult.html) uses.
Modifying a blocking GPO
You can modify these settings in the Group Policy Object Editor (GPE) and Group Policy Management Console (GPM). For more information about how to use Group Policy, see Advanced Group Policy Management.
To modify the blocking policy, use one of the following methods:
In GPE, access the appropriate level of GPO (such as local or domain), and navigate to Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Connections > Allow users to connect remotely by using Remote Desktop Services.
Set the policy to either Enabled or Not configured.
On the affected computers, open a command prompt window as an administrator, and run the gpupdate /force command.
In GPM, navigate to the organizational unit (OU) in which the blocking policy is applied to the affected computers and delete the policy from the OU.
Check the status of the RDP services
On both the local (client) computer and the remote (target) computer, the following services should be running:
Remote Desktop Services (TermService)
Remote Desktop Services UserMode Port Redirector (UmRdpService)
You can use the Services MMC snap-in to manage the services locally or remotely. You can also use PowerShell to manage the services locally or remotely (if the remote computer is configured to accept remote PowerShell cmdlets).
On either computer, if one or both services are not running, start them.
Note
If you start the Remote Desktop Services service, click Yes to automatically restart the Remote Desktop Services UserMode Port Redirector service.
Check that the RDP listener is functioning
Important
Follow this section’s instructions carefully. Serious problems can occur if the registry is modified incorrectly. Before you starty modifying the registry, back up the registry so you can restore it in case something goes wrong.
Check the status of the RDP listener
For this procedure, use a PowerShell instance that has administrative permissions. For a local computer, you can also use a command prompt that has administrative permissions. However, this procedure uses PowerShell because the same cmdlets work both locally and remotely.
To connect to a remote computer, run the following cmdlet:PowerShellCopyEnter-PSSession -ComputerName <computer name>
Enter qwinsta.
If the list includes rdp-tcp with a status of Listen, the RDP listener is working. Proceed to Check the RDP listener port. Otherwise, continue at step 4.
Export the RDP listener configuration from a working computer.
Sign in to a computer that has the same operating system version as the affected computer has, and access that computer’s registry (for example, by using Registry Editor).
Navigate to the following registry entry: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp
Export the entry to a .reg file. For example, in Registry Editor, right-click the entry, select Export, and then enter a filename for the exported settings.
Copy the exported .reg file to the affected computer.
To import the RDP listener configuration, open a PowerShell window that has administrative permissions on the affected computer (or open the PowerShell window and connect to the affected computer remotely).
To back up the existing registry entry, enter the following cmdlet:PowerShellCopycmd /c 'reg export "HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-tcp" C:\Rdp-tcp-backup.reg'
To remove the existing registry entry, enter the following cmdlets:PowerShellCopyRemove-Item -path 'HKLM:\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-tcp' -Recurse -Force
To import the new registry entry and then restart the service, enter the following cmdlets:PowerShellCopycmd /c 'regedit /s c:\<filename>.reg' Restart-Service TermService -Force Replace <filename> with the name of the exported .reg file.
Test the configuration by trying the remote desktop connection again. If you still can’t connect, restart the affected computer.
Check the status of the RDP self-signed certificate
If you still can’t connect, open the Certificates MMC snap-in. When you are prompted to select the certificate store to manage, select Computer account, and then select the affected computer.
In the Certificates folder under Remote Desktop, delete the RDP self-signed certificate.
On the affected computer, restart the Remote Desktop Services service.
On the affected computer, open Explorer, and then navigate to C:\ProgramData\Microsoft\Crypto\RSA\.
Right-click MachineKeys, select Properties, select Security, and then select Advanced.
Make sure that the following permissions are configured:
Builtin\Administrators: Full control
Everyone: Read, Write
Check the RDP listener port
On both the local (client) computer and the remote (target) computer, the RDP listener should be listening on port 3389. No other applications should be using this port.
Important
Follow this section’s instructions carefully. Serious problems can occur if the registry is modified incorrectly. Before you starty modifying the registry, back up the registry so you can restore it in case something goes wrong.
To check or change the RDP port, use the Registry Editor:
Go to the Start menu, select Run, then enter regedt32 into the text box that appears.
To connect to a remote computer, select File, and then select Connect Network Registry.
In the Select Computer dialog box, enter the name of the remote computer, select Check Names, and then select OK.
Open the registry and navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\<listener>.
If PortNumber has a value other than 3389, change it to 3389. ImportantYou can operate Remote Desktop services using another port. However, we don’t recommend you do this. This article doesn’t cover how to troubleshoot that type of configuration.
After you change the port number, restart the Remote Desktop Services service.
Check that another application isn’t trying to use the same port
For this procedure, use a PowerShell instance that has administrative permissions. For a local computer, you can also use a command prompt that has administrative permissions. However, this procedure uses PowerShell because the same cmdlets work locally and remotely.
Open a PowerShell window. To connect to a remote computer, enter Enter-PSSession -ComputerName <computer name>.
Enter the following command:PowerShellCopycmd /c 'netstat -ano | find "3389"'
Look for an entry for TCP port 3389 (or the assigned RDP port) with a status of Listening. NoteThe process identifier (PID) for the process or service using that port appears under the PID column.
To determine which application is using port 3389 (or the assigned RDP port), enter the following command:PowerShellCopycmd /c 'tasklist /svc | find "<pid listening on 3389>"'
Look for an entry for the PID number that is associated with the port (from the netstat output). The services or processes that are associated with that PID appear on the right column.
If an application or service other than Remote Desktop Services (TermServ.exe) is using the port, you can resolve the conflict by using one of the following methods:
Configure the other application or service to use a different port (recommended).
Uninstall the other application or service.
Configure RDP to use a different port, and then restart the Remote Desktop Services service (not recommended).
Check whether a firewall is blocking the RDP port
Use the psping tool to test whether you can reach the affected computer by using port 3389.
Open a command prompt window as an administrator, change to the directory in which you installed psping, and then enter the following command:Copypsping -accepteula <computer IP>:3389
Check the output of the psping command for results such as the following:
Connecting to <computer IP>: The remote computer is reachable.
(0% loss): All attempts to connect succeeded.
The remote computer refused the network connection: The remote computer is not reachable.
(100% loss): All attempts to connect failed.
Run psping on multiple computers to test their ability to connect to the affected computer.
Note whether the affected computer blocks connections from all other computers, some other computers, or only one other computer.
Recommended next steps:
Engage your network administrators to verify that the network allows RDP traffic to the affected computer.
Investigate the configurations of any firewalls between the source computers and the affected computer (including Windows Firewall on the affected computer) to determine whether a firewall is blocking the RDP port.
This was a weekend of record-breaking DDoS attacks. Over the weekend, Cloudflare detected and mitigated dozens of hyper-volumetric DDoS attacks. The majority of attacks peaked in the ballpark of 50-70 million requests per second (rps) with the largest exceeding 71 million rps. This is the largest reported HTTP DDoS attack on record, more than 35% higher than the previous reported record of 46M rps in June 2022.
The attacks were HTTP/2-based and targeted websites protected by Cloudflare. They originated from over 30,000 IP addresses. Some of the attacked websites included a popular gaming provider, cryptocurrency companies, hosting providers, and cloud computing platforms. The attacks originated from numerous cloud providers, and we have been working with them to crack down on the botnet.
Record breaking attack: DDoS attack exceeding 71 million requests per second
Over the past year, we’ve seen more attacks originate from cloud computing providers. For this reason, we will be providing service providers that own their own autonomous system a free Botnet threat feed. The feed will provide service providers threat intelligence about their own IP space; attacks originating from within their autonomous system. Service providers that operate their own IP space can now sign up to the early access waiting list.
Is this related to the Super Bowl or Killnet?
No. This campaign of attacks arrives less than two weeks after the Killnet DDoS campaign that targeted healthcare websites. Based on the methods and targets, we do not believe that these recent attacks are related to the healthcare campaign. Furthermore, yesterday was the US Super Bowl, and we also do not believe that this attack campaign is related to the game event.
What are DDoS attacks?
Distributed Denial of Service attacks are cyber attacks that aim to take down Internet properties and make them unavailable for users. These types of cyberattacks can be very efficient against unprotected websites and they can be very inexpensive for the attackers to execute.
An HTTP DDoS attack usually involves a flood of HTTP requests towards the target website. The attacker’s objective is to bombard the website with more requests than it can handle. Given a sufficiently high amount of requests, the website’s server will not be able to process all of the attack requests along with the legitimate user requests. Users will experience this as website-load delays, timeouts, and eventually not being able to connect to their desired websites at all.
Illustration of a DDoS attack
To make attacks larger and more complicated, attackers usually leverage a network of bots — a botnet. The attacker will orchestrate the botnet to bombard the victim’s websites with HTTP requests. A sufficiently large and powerful botnet can generate very large attacks as we’ve seen in this case.
However, building and operating botnets requires a lot of investment and expertise. What is the average Joe to do? Well, an average Joe that wants to launch a DDoS attack against a website doesn’t need to start from scratch. They can hire one of numerous DDoS-as-a-Service platforms for as little as $30 per month. The more you pay, the larger and longer of an attack you’re going to get.
Why DDoS attacks?
Over the years, it has become easier, cheaper, and more accessible for attackers and attackers-for-hire to launch DDoS attacks. But as easy as it has become for the attackers, we want to make sure that it is even easier – and free – for defenders of organizations of all sizes to protect themselves against DDoS attacks of all types.
Unlike Ransomware attacks, Ransom DDoS attacks don’t require an actual system intrusion or a foothold within the targeted network. Usually Ransomware attacks start once an employee naively clicks an email link that installs and propagates the malware. There’s no need for that with DDoS attacks. They are more like a hit-and-run attack. All a DDoS attacker needs to know is the website’s address and/or IP address.
Is there an increase in DDoS attacks?
Yes. The size, sophistication, and frequency of attacks has been increasing over the past months. In our latest DDoS threat report, we saw that the amount of HTTP DDoS attacks increased by 79% year-over-year. Furthermore, the amount of volumetric attacks exceeding 100 Gbps grew by 67% quarter-over-quarter (QoQ), and the number of attacks lasting more than three hours increased by 87% QoQ.
But it doesn’t end there. The audacity of attackers has been increasing as well. In our latest DDoS threat report, we saw that Ransom DDoS attacks steadily increased throughout the year. They peaked in November 2022 where one out of every four surveyed customers reported being subject to Ransom DDoS attacks or threats.
Distribution of Ransom DDoS attacks by month
Should I be worried about DDoS attacks?
Yes. If your website, server, or networks are not protected against volumetric DDoS attacks using a cloud service that provides automatic detection and mitigation, we really recommend that you consider it.
Cloudflare customers shouldn’t be worried, but should be aware and prepared. Below is a list of recommended steps to ensure your security posture is optimized.
What steps should I take to defend against DDoS attacks?
Cloudflare’s systems have been automatically detecting and mitigating these DDoS attacks.
Cloudflare offers many features and capabilities that you may already have access to but may not be using. So as extra precaution, we recommend taking advantage of these capabilities to improve and optimize your security posture:
Ensure all DDoS Managed Rules are set to default settings (High sensitivity level and mitigation actions) for optimal DDoS activation.
Cloudflare Enterprise customers that are subscribed to the Advanced DDoS Protection service should consider enabling Adaptive DDoS Protection, which mitigates attacks more intelligently based on your unique traffic patterns.
Deploy firewall rules and rate limiting rules to enforce a combined positive and negative security model. Reduce the traffic allowed to your website based on your known usage.
Ensure your origin is not exposed to the public Internet (i.e., only enable access to Cloudflare IP addresses). As an extra security precaution, we recommend contacting your hosting provider and requesting new origin server IPs if they have been targeted directly in the past.
Customers with access to Managed IP Lists should consider leveraging those lists in firewall rules. Customers with Bot Management should consider leveraging the threat scores within the firewall rules.
Enable caching as much as possible to reduce the strain on your origin servers, and when using Workers, avoid overwhelming your origin server with more subrequests than necessary.
Defending against DDoS attacks is critical for organizations of all sizes. While attacks may be initiated by humans, they are executed by bots — and to play to win, you must fight bots with bots. Detection and mitigation must be automated as much as possible, because relying solely on humans to mitigate in real time puts defenders at a disadvantage. Cloudflare’s automated systems constantly detect and mitigate DDoS attacks for our customers, so they don’t have to. This automated approach, combined with our wide breadth of security capabilities, lets customers tailor the protection to their needs.
We’ve been providing unmetered and unlimited DDoS protection for free to all of our customers since 2017, when we pioneered the concept. Cloudflare’s mission is to help build a better Internet. A better Internet is one that is more secure, faster, and reliable for everyone – even in the face of DDoS attacks.
Visit 1.1.1.1 from any device to get started with our free app that makes your Internet faster and safer.
To learn more about our mission to help build a better Internet, start here. If you’re looking for a new career direction, check out our open positions.
Here are three of the worst breaches, attacker tactics and techniques of 2022, and the security controls that can provide effective, enterprise security protection for them.
Ransomware as a service is a type of attack in which the ransomware software and infrastructure are leased out to the attackers. These ransomware services can be purchased on the dark web from other threat actors and ransomware gangs. Common purchasing plans include buying the entire tool, using the existing infrastructure while paying per infection, or letting other attackers perform the service while sharing revenue with them.
In this attack, the threat actor consists of one of the most prevalent ransomware groups, specializing in access via third parties, while the targeted company is a medium-sized retailer with dozens of sites in the United States.
The threat actors used ransomware as a service to breach the victim’s network. They were able to exploit third-party credentials to gain initial access, progress laterally, and ransom the company, all within mere minutes.
The swiftness of this attack was unusual. In most RaaS cases, attackers usually stay in the networks for weeks and months before demanding ransom. What is particularly interesting about this attack is that the company was ransomed in minutes, with no need for discovery or weeks of lateral movement.
A log investigation revealed that the attackers targeted servers that did not exist in this system. As it turns out, the victim was initially breached and ransomed 13 months before this second ransomware attack. Subsequently, the first attacker group monetized the first attack not only through the ransom they obtained, but also by selling the company’s network information to the second ransomware group.
In the 13 months between the two attacks, the victim changed its network and removed servers, but the new attackers were not aware of these architectural modifications. The scripts they developed were designed for the previous network map. This also explains how they were able to attack so quickly – they had plenty of information about the network. The main lesson here is that ransomware attacks can be repeated by different groups, especially if the victim pays well.
“RaaS attacks such as this one are a good example of how full visibility allows for early alerting. A global, converged, cloud-native SASE platform that supports all edges, like Cato Networks provides complete network visibility into network events that are invisible to other providers or may go under the radar as benign events. And, being able to fully contextualize the events allows for early detection and remediation.
#2: The Critical Infrastructure Attack on Radiation Alert Networks#
Attacks on critical infrastructure are becoming more common and more dangerous. Breaches of water supply plants, sewage systems and other such infrastructures could put millions of residents at risk of a human crisis. These infrastructures are also becoming more vulnerable, and attack surface management tools for OSINT like Shodan and Censys allow security teams to find such vulnerabilities with ease.
In 2021, two hackers were suspected of targeting radiation alert networks. Their attack relied on two insiders that worked for a third party. These insiders disabled the radiation alert systems, significantly debilitating their ability to monitor radiation attacks. The attackers were then able to delete critical software and disable radiation gauges (which is part of the infrastructure itself).
“Unfortunately, scanning for vulnerable systems in critical infrastructure is easier than ever. While many such organizations have multiple layers of security, they are still using point solutions to try and defend their infrastructure rather than one system that can look holistically at the full attack lifecycle. Breaches are never just a phishing problem, or a credentials problem, or a vulnerable system problem – they are always a combination of multiple compromises performed by the threat actor,” said Etay Maor, Sr. Director of Security Strategy at Cato Networks.
#3: The Three-Step Ransomware Attack That Started with Phishing#
The third attack is also a ransomware attack. This time, it consisted of three steps:
1. Infiltration – The attacker was able to gain access to the network through a phishing attack. The victim clicked on a link that generated a connection to an external site, which resulted in the download of the payload.
2. Network activity – In the second phase, the attacker progressed laterally in the network for two weeks. During this time, it collected admin passwords and used in-memory fileless malware. Then on New Year’s Eve, it performed the encryption. This date was chosen since it was (rightfully) assumed the security team would be off on vacation.
3. Exfiltration – Finally, the attackers uploaded the data out of the network.
In addition to these three main steps, additional sub-techniques were employed during the attack and the victim’s point security solutions were not able to block this attack.
“A multiple choke point approach, one that looks horizontally (so to speak) at the attack rather than as a set of vertical, disjointed issues, is the way to enhance detection, mitigation and prevention of such threats. Opposed to popular belief, the attacker needs to be right many times and the defenders only need to be right just once. The underlying technologies to implement a multiple choke point approach are full network visibility via a cloud-native backbone, and a single pass security stack that’s based on ZTNA.” said Etay Maor, Sr. Director of Security Strategy at Cato Networks.
It is common for security professionals to succumb to the “single point of failure fallacy”. However, cyber-attacks are sophisticated events that rarely involve just one tactic or technique which is the cause of the breach. Therefore, an all-encompassing outlook is required to successfully mitigate cyber-attacks. Security point solutions are a solution for single points of failure. These tools can identify risks, but they will not connect the dots, which could and has led to a breach.
According to ongoing security research conducted by Cato Networks Security Team, they have identified two additional vulnerabilities and exploit attempts that they recommend including in your upcoming security plans:
While Log4j made its debut as early as December of 2021, the noise its making hasn’t died down. Log4j is still being used by attackers to exploit systems, as not all organizations have been able to patch their Log4j vulnerabilities or detect Log4j attacks, in what is known as “virtual patching”. They recommend prioritizing Log4j mitigation.
Security solutions like firewalls and VPNs have become access points for attackers. Patching them has become increasingly difficult, especially in the era of architecture cloudification and remote work. It is recommended to pay close attention to these components as they are increasingly vulnerable.
How to Minimize Your Attack Surface and Gain Visibility into the Network#
To reduce the attack surface, security professionals need visibility into their networks. Visibility relies on three pillars:
Actionable information – that can be used to mitigate attacks
Reliable information – that minimizes the number of false positives
Timely information – to ensure mitigation happens before the attack has an impact
Once an organization has complete visibility to the activity on their network they can contextualize the data, decide whether the activity witnessed should be allowed, denied, monitored, restricted (or any other action) and then have the ability to enforce this decision. All these elements must be applied to every entity, be it a user, device, cloud app etc. All the time everywhere. That is what SASE is all about.
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Multiple vulnerabilities in VMware ESXi and vSphere Client (HTML5) were privately reported to VMware. Updates are available to remediate these vulnerabilities in affected VMware products.
3a. VMware vCenter Server updates address remote code execution vulnerability in the vSphere Client (CVE-2021-21972)
Description
The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin. VMware has evaluated the severity of this issue to be in the Critical severity range with a maximum CVSSv3 base score of 9.8.
Known Attack Vectors
A malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server.
Resolution
To remediate CVE-2021-21972 apply the updates listed in the ‘Fixed Version’ column of the ‘Response Matrix’ below to affected deployments.
Workarounds
Workarounds for CVE-2021-21972 have been listed in the ‘Workarounds’ column of the ‘Response Matrix’ below.
Additional Documentation
None.
Notes
The affected vCenter Server plugin for vROPs is available in all default installations. vROPs does not need be present to have this endpoint available. Follow the workarounds KB to disable it.
Acknowledgements
VMware would like to thank Mikhail Klyuchnikov of Positive Technologies for reporting this issue to us.
OpenSLP as used in ESXi has a heap-overflow vulnerability. VMware has evaluated the severity of this issue to be in the Important severity range with a maximum CVSSv3 base score of 8.8.
Known Attack Vectors
A malicious actor residing within the same network segment as ESXi who has access to port 427 may be able to trigger the heap-overflow issue in OpenSLP service resulting in remote code execution.
Resolution
To remediate CVE-2021-21974 apply the updates listed in the ‘Fixed Version’ column of the ‘Response Matrix’ below to affected deployments.
Workarounds
Workarounds for CVE-2021-21974 have been listed in the ‘Workarounds’ column of the ‘Response Matrix’ below.
3c. VMware vCenter Server updates address SSRF vulnerability in the vSphere Client (CVE-2021-21973)
Description
The vSphere Client (HTML5) contains an SSRF (Server Side Request Forgery) vulnerability due to improper validation of URLs in a vCenter Server plugin. VMware has evaluated the severity of this issue to be in the Moderate severity range with a maximum CVSSv3 base score of 5.3.
Known Attack Vectors
A malicious actor with network access to port 443 may exploit this issue by sending a POST request to vCenter Server plugin leading to information disclosure.
Resolution
To remediate CVE-2021-21973 apply the updates listed in the ‘Fixed Version’ column of the ‘Response Matrix’ below to affected deployments.
Workarounds
Workarounds for CVE-2021-21973 have been listed in the ‘Workarounds’ column of the ‘Response Matrix’ below.
Additional Documentation
None.
Notes
The affected vCenter Server plugin for vROPs is available in all default installations. vROPs does not need be present to have this endpoint available. Follow the workarounds KB to disable it.
Acknowledgements
VMware would like to thank Mikhail Klyuchnikov of Positive Technologies for reporting this issue to us.
