Cybercriminals are exploiting poorly secured and public-facing Microsoft SQL servers to deploy the Trigona ransomware. The ransomware strain was discovered in October 2022 and shares similarities with CryLock ransomware.
Attackers use brute-force or dictionary attacks to guess account credentials and gain access to the server, before deploying CLR Shell malware to harvest system information and escalate privileges to LocalSystem by exploiting a vulnerability in the Windows Secondary Logon Service.
The malware is confirmed to exploit privilege escalation vulnerabilities, which are believed to be due to the high privileges required by Trigona as it operates as a service.
Once the attackers gain control of the server, they install Trigona under the name svcservice.exe, which executes the ransomware and creates svchost.bat to register the Trigona binary to the Run key to maintain persistence. The ransomware encrypts files without distinguishing their extensions and appends the “._locked” extension to the filename of encrypted files.
The ransomware also deletes volume shadow copies and disables the system recovery feature to prevent victims from recovering their files. The ransom note includes instructions to contact the Trigona operators and contains a link to the Trigona Tor negotiation website.
To protect against such attacks, administrators must use strong passwords and change them periodically, update V3 to the latest version, and use security programs such as firewalls for database servers accessible from outside to restrict access by external threat actors.
Failure to take these measures can lead to continuous infections by threat actors and malware. With the rise of cyberattacks targeting poorly secured servers, organizations must ensure that they keep their systems updated and secure.
