Phorpiex Botnet Now Deploying LockBit Ransomware in Automated Attacks
Summary:
The Cybereason Security Team has recently published an analysis of a new attack campaign involving the Phorpiex botnet. In this campaign, the botnet is being used to automatically deploy LockBit Black Ransomware. This differs from previous attacks, which often relied on human interaction from LockBit operators, by making the attacks faster and more difficult to detect via the botnet. Phorpiex is also known as Trik and has been active since at least 2010. In the past, the botnet was mainly used for spam campaigns that distributed malware including cryptocurrency mining malware. The source code to the botnet was sold in 2021, but attacks observed after that reveal that there were minimal changes to the codebase. LockBit affiliates are now leveraging Phorpiex as a tool to more effectively compromise systems with ransomware.
The infection chain begins with the delivery of phishing emails from spoofed senders containing malicious ZIP files as the initial infection vector. At this point, the infection chain forks into two variants. In one of them, the ZIP file delivers the LockBit downloader version of Phorpiex in the form of a SCR file and the other delivers the TWITZ malware downloader variant as a LNK file. Once the malicious SCR file is executed, it establishes a connection to 193.233.132[.]177, a Command-and-Control (C2) server, downloads the LockBit binary (lbbb.exe) to the %TEMP% directory, and executes the ransomware payload for double extortion.
Security Officer Comments:
Unlike how ransomware payloads usually operate, this version does not attempt lateral movement. It immediately executes LockBit to reduce the chances of detection from defenders. In addition to reducing its footprint, it boasts multiple defense evasion tactics such as deleting URL cache, obfuscating function calls, removing C2 origin metadata from security logs, and modifying the Windows registry to automatically run LockBit at startup. The use of LockBit by affiliates in conjunction with a botnet like Phorpiex underscores the ever-evolving tactics of ransomware deployment. Automating the deployment of LockBit with the botnet expands the reach of the campaign, increases successful infections, and reduces detection using the botnet’s built-in sandbox evasion capabilities. Performing network traffic and behavioral analysis with the assistance of signature-based detection tools and honeypots for reactive security can help defenders detect unusual spikes in traffic or anomalies in system activity and contain malicious activity. Remaining vigilant for suspicious emails or messages and unusual file activity is important as these are intimations of ransomware activity.
Suggested Corrections:
IOCs are available here.
Backup your data, system images, and configurations, regularly test them, and keep the backups offline: Ensure that backups are regularly tested and that they are not connected to the business network, as many ransomware variants try to find and encrypt or delete accessible backups. Maintaining current backups offline is critical because if your network data is encrypted with ransomware, your organization can restore systems.
Update and patch systems promptly: This includes maintaining the security of operating systems, applications, and firmware in a timely manner. Consider using a centralized patch management system; use a risk-based assessment strategy to drive your patch management program.
Test your incident response plan: There's nothing that shows the gaps in plans more than testing them. Run through some core questions and use those to build an incident response plan: Are you able to sustain business operations without access to certain systems? For how long? Would you turn off your manufacturing operations if business systems such as billing were offline?
Check Your Security Team's Work: Use a 3rd party pen tester to test the security of your systems and your ability to defend against a sophisticated attack. Many ransomware criminals are aggressive and sophisticated and will find the equivalent of unlocked doors.
Segment your networks: There's been a recent shift in ransomware attacks – from stealing data to disrupting operations. It's critically important that your corporate business functions and manufacturing/production operations are separated and that you carefully filter and limit internet access to operational networks, identify links between these networks, and develop workarounds or manual controls to ensure ICS networks can be isolated and continue operating if your corporate network is compromised. Regularly test contingency plans such as manual controls so that safety-critical functions can be maintained during a cyber incident.
Train employees: Email remains the most vulnerable attack vector for organizations. Users should be trained on how to avoid and spot phishing emails. Multi-factor authentication can help prevent malicious access to sensitive services.
Link(s):
https://securityonline.info/phorpiex-botnet-now-deploying-lockbit-ransomware-in-automated-attacks/
https://www.cybereason.com/blog/threat-analysis-phorpiex-downloader
The Cybereason Security Team has recently published an analysis of a new attack campaign involving the Phorpiex botnet. In this campaign, the botnet is being used to automatically deploy LockBit Black Ransomware. This differs from previous attacks, which often relied on human interaction from LockBit operators, by making the attacks faster and more difficult to detect via the botnet. Phorpiex is also known as Trik and has been active since at least 2010. In the past, the botnet was mainly used for spam campaigns that distributed malware including cryptocurrency mining malware. The source code to the botnet was sold in 2021, but attacks observed after that reveal that there were minimal changes to the codebase. LockBit affiliates are now leveraging Phorpiex as a tool to more effectively compromise systems with ransomware.
The infection chain begins with the delivery of phishing emails from spoofed senders containing malicious ZIP files as the initial infection vector. At this point, the infection chain forks into two variants. In one of them, the ZIP file delivers the LockBit downloader version of Phorpiex in the form of a SCR file and the other delivers the TWITZ malware downloader variant as a LNK file. Once the malicious SCR file is executed, it establishes a connection to 193.233.132[.]177, a Command-and-Control (C2) server, downloads the LockBit binary (lbbb.exe) to the %TEMP% directory, and executes the ransomware payload for double extortion.
Security Officer Comments:
Unlike how ransomware payloads usually operate, this version does not attempt lateral movement. It immediately executes LockBit to reduce the chances of detection from defenders. In addition to reducing its footprint, it boasts multiple defense evasion tactics such as deleting URL cache, obfuscating function calls, removing C2 origin metadata from security logs, and modifying the Windows registry to automatically run LockBit at startup. The use of LockBit by affiliates in conjunction with a botnet like Phorpiex underscores the ever-evolving tactics of ransomware deployment. Automating the deployment of LockBit with the botnet expands the reach of the campaign, increases successful infections, and reduces detection using the botnet’s built-in sandbox evasion capabilities. Performing network traffic and behavioral analysis with the assistance of signature-based detection tools and honeypots for reactive security can help defenders detect unusual spikes in traffic or anomalies in system activity and contain malicious activity. Remaining vigilant for suspicious emails or messages and unusual file activity is important as these are intimations of ransomware activity.
Suggested Corrections:
IOCs are available here.
Backup your data, system images, and configurations, regularly test them, and keep the backups offline: Ensure that backups are regularly tested and that they are not connected to the business network, as many ransomware variants try to find and encrypt or delete accessible backups. Maintaining current backups offline is critical because if your network data is encrypted with ransomware, your organization can restore systems.
Update and patch systems promptly: This includes maintaining the security of operating systems, applications, and firmware in a timely manner. Consider using a centralized patch management system; use a risk-based assessment strategy to drive your patch management program.
Test your incident response plan: There's nothing that shows the gaps in plans more than testing them. Run through some core questions and use those to build an incident response plan: Are you able to sustain business operations without access to certain systems? For how long? Would you turn off your manufacturing operations if business systems such as billing were offline?
Check Your Security Team's Work: Use a 3rd party pen tester to test the security of your systems and your ability to defend against a sophisticated attack. Many ransomware criminals are aggressive and sophisticated and will find the equivalent of unlocked doors.
Segment your networks: There's been a recent shift in ransomware attacks – from stealing data to disrupting operations. It's critically important that your corporate business functions and manufacturing/production operations are separated and that you carefully filter and limit internet access to operational networks, identify links between these networks, and develop workarounds or manual controls to ensure ICS networks can be isolated and continue operating if your corporate network is compromised. Regularly test contingency plans such as manual controls so that safety-critical functions can be maintained during a cyber incident.
Train employees: Email remains the most vulnerable attack vector for organizations. Users should be trained on how to avoid and spot phishing emails. Multi-factor authentication can help prevent malicious access to sensitive services.
Link(s):
https://securityonline.info/phorpiex-botnet-now-deploying-lockbit-ransomware-in-automated-attacks/
https://www.cybereason.com/blog/threat-analysis-phorpiex-downloader