New 'Helldown' Ransomware Variant Expands Attacks to VMware and Linux Systems
Summary:
Helldown, a ransomware strain derived from the leaked LockBit 3.0 codebase, has been expanding its operations, with researchers recently identifying a Linux variant. This development indicates the group's growing focus on targeting virtualized infrastructures, such as VMware. First documented in August 2024, Helldown has been described as an aggressive ransomware group targeting sectors like IT services, telecommunications, manufacturing, and healthcare. It employs double extortion tactics, threatening to publish stolen data to pressure victims into paying ransoms. The group has reportedly attacked at least 31 companies within three months. Helldown's attack chains often begin with exploiting vulnerabilities in Zyxel firewalls, allowing the attackers to breach networks, steal credentials, and establish SSL VPN tunnels. The Windows variant of the ransomware deletes system shadow copies, terminates critical processes like databases and Microsoft Office, exfiltrates and encrypts files, drops a ransom note, and shuts down the machine to conceal its tracks. The Linux variant, while lacking advanced features like obfuscation or anti-debugging mechanisms, incorporates functionality to kill virtual machines, although this feature has not been observed in use, suggesting that it may still be under development.
Analyst Comments:
Researchers have noted behavioral similarities between Helldown and other ransomware families like DarkRace, later rebranded to DoNex, both of which originated from the LockBit 3.0 source code. This raises the possibility that Helldown itself may be another rebrand, though this connection has not been definitively confirmed. The emergence of other ransomware families, such as Interlock and SafePay, highlights a broader trend in the ransomware ecosystem. Interlock, targeting healthcare, technology, and government sectors, uses fake Google Chrome updates to distribute remote access trojans for reconnaissance and credential theft. SafePay, also derived from LockBit 3.0, has reportedly attacked 22 companies, accessing networks via compromised VPN gateways without creating new accounts or enabling RDP.
Suggested Corrections:
IOCs:
https://blog.sekoia.io/helldown-ransomware-an-overview-of-this-emerging-threat/#h-conclusion
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://thehackernews.com/2024/11/new-helldown-ransomware-expands-attacks.html
https://blog.sekoia.io/helldown-ransomware-an-overview-of-this-emerging-threat/
Helldown, a ransomware strain derived from the leaked LockBit 3.0 codebase, has been expanding its operations, with researchers recently identifying a Linux variant. This development indicates the group's growing focus on targeting virtualized infrastructures, such as VMware. First documented in August 2024, Helldown has been described as an aggressive ransomware group targeting sectors like IT services, telecommunications, manufacturing, and healthcare. It employs double extortion tactics, threatening to publish stolen data to pressure victims into paying ransoms. The group has reportedly attacked at least 31 companies within three months. Helldown's attack chains often begin with exploiting vulnerabilities in Zyxel firewalls, allowing the attackers to breach networks, steal credentials, and establish SSL VPN tunnels. The Windows variant of the ransomware deletes system shadow copies, terminates critical processes like databases and Microsoft Office, exfiltrates and encrypts files, drops a ransom note, and shuts down the machine to conceal its tracks. The Linux variant, while lacking advanced features like obfuscation or anti-debugging mechanisms, incorporates functionality to kill virtual machines, although this feature has not been observed in use, suggesting that it may still be under development.
Analyst Comments:
Researchers have noted behavioral similarities between Helldown and other ransomware families like DarkRace, later rebranded to DoNex, both of which originated from the LockBit 3.0 source code. This raises the possibility that Helldown itself may be another rebrand, though this connection has not been definitively confirmed. The emergence of other ransomware families, such as Interlock and SafePay, highlights a broader trend in the ransomware ecosystem. Interlock, targeting healthcare, technology, and government sectors, uses fake Google Chrome updates to distribute remote access trojans for reconnaissance and credential theft. SafePay, also derived from LockBit 3.0, has reportedly attacked 22 companies, accessing networks via compromised VPN gateways without creating new accounts or enabling RDP.
Suggested Corrections:
IOCs:
https://blog.sekoia.io/helldown-ransomware-an-overview-of-this-emerging-threat/#h-conclusion
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://thehackernews.com/2024/11/new-helldown-ransomware-expands-attacks.html
https://blog.sekoia.io/helldown-ransomware-an-overview-of-this-emerging-threat/