New VanHelsing Ransomware Targets Windows, Arm, Esxi Systems
Summary:
Launched on March 7, 2025, VanHelsingRaaS is a rapidly growing ransomware-as-a-service platform that has already infected at least three known victims within its first two weeks of operation. Affiliates can join by paying a $5,000 deposit, though reputable affiliates may be invited for free—and receive 80% of ransom proceeds, with the remaining 20% going to the core operators. The service enforces one key rule: affiliates must not target systems in Commonwealth of Independent States countries, a typical restriction observed in Russian-speaking cybercriminal circles. The platform supports a wide range of systems, including Windows, Linux, BSD, ARM, and ESXi, significantly broadening its reach. It also provides affiliates with a streamlined and user-friendly control panel to coordinate and manage their ransomware campaigns.
Check Point Research analyzed two Windows variants of VanHelsing ransomware, compiled just five days apart, highlighting the malware’s rapid development cycle. The ransomware is written in C++ and supports a variety of command-line arguments that allow attackers to tailor the encryption process—such as selecting specific files, folders, or drives, excluding network or mounted volumes, suppressing logs, or enabling SMB spreading. It can run in a "Silent" mode, encrypting files without changing their extensions until a second renaming pass, allowing it to evade behavioral detection tools. Infected systems are left with a ransom note demanding payment in Bitcoin and warning against third-party decryption tools.
The ransomware uses Curve25519 for public key cryptography and ChaCha20 for encrypting file contents, generating unique keys and nonces for each file. For large files, only the first 30% is encrypted, while smaller files are fully encrypted in 1MB chunks. The resulting encrypted files contain embedded key and nonce data in a custom format and are typically renamed with a .vanhelsing extension. However, an inconsistency in the ransomware's code mistakenly excludes .vanlocker files, not .vanhelsing, from double-encryption, revealing a flaw in file extension handling.Security Officer Comments:
In addition to local drive encryption, the ransomware scans local IP ranges for open SMB (port 445) services to identify shared folders and can spread laterally using PsExec, dropping itself onto writable network shares and executing remotely. Shadow copies are deleted via WMI queries, making recovery difficult. The malware also avoids encrypting specific system-critical files and folders to prevent total system failure, allowing the system to remain functional and potentially facilitating ransom payment.
Suggested Corrections:
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.
Implement multi-factor authentication (MFA): External-facing assets that leverage single-factor authentication (SFA) are highly susceptible to brute-forcing attacks, password spraying, or unauthorized remote access using valid (stolen) credentials. Implementing MFA enhances security and adds an extra layer of protection.
Link(s):
https://www.bleepingcomputer.com/ne...-ransomware-targets-windows-arm-esxi-systems/
Launched on March 7, 2025, VanHelsingRaaS is a rapidly growing ransomware-as-a-service platform that has already infected at least three known victims within its first two weeks of operation. Affiliates can join by paying a $5,000 deposit, though reputable affiliates may be invited for free—and receive 80% of ransom proceeds, with the remaining 20% going to the core operators. The service enforces one key rule: affiliates must not target systems in Commonwealth of Independent States countries, a typical restriction observed in Russian-speaking cybercriminal circles. The platform supports a wide range of systems, including Windows, Linux, BSD, ARM, and ESXi, significantly broadening its reach. It also provides affiliates with a streamlined and user-friendly control panel to coordinate and manage their ransomware campaigns.
Check Point Research analyzed two Windows variants of VanHelsing ransomware, compiled just five days apart, highlighting the malware’s rapid development cycle. The ransomware is written in C++ and supports a variety of command-line arguments that allow attackers to tailor the encryption process—such as selecting specific files, folders, or drives, excluding network or mounted volumes, suppressing logs, or enabling SMB spreading. It can run in a "Silent" mode, encrypting files without changing their extensions until a second renaming pass, allowing it to evade behavioral detection tools. Infected systems are left with a ransom note demanding payment in Bitcoin and warning against third-party decryption tools.
The ransomware uses Curve25519 for public key cryptography and ChaCha20 for encrypting file contents, generating unique keys and nonces for each file. For large files, only the first 30% is encrypted, while smaller files are fully encrypted in 1MB chunks. The resulting encrypted files contain embedded key and nonce data in a custom format and are typically renamed with a .vanhelsing extension. However, an inconsistency in the ransomware's code mistakenly excludes .vanlocker files, not .vanhelsing, from double-encryption, revealing a flaw in file extension handling.Security Officer Comments:
In addition to local drive encryption, the ransomware scans local IP ranges for open SMB (port 445) services to identify shared folders and can spread laterally using PsExec, dropping itself onto writable network shares and executing remotely. Shadow copies are deleted via WMI queries, making recovery difficult. The malware also avoids encrypting specific system-critical files and folders to prevent total system failure, allowing the system to remain functional and potentially facilitating ransom payment.
Suggested Corrections:
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.
Implement multi-factor authentication (MFA): External-facing assets that leverage single-factor authentication (SFA) are highly susceptible to brute-forcing attacks, password spraying, or unauthorized remote access using valid (stolen) credentials. Implementing MFA enhances security and adds an extra layer of protection.
Link(s):
https://www.bleepingcomputer.com/ne...-ransomware-targets-windows-arm-esxi-systems/