The Cactus Ransomware Group's Attack on Ammega

The Cactus ransomware group has attacked Ammega. The attack resulted in the exfiltration of 1TB of data, now available for sale on the dark web. Ammega is a multinational automation machinery manufacturing company headquartered in the Netherlands. It has over 10,000 employees and a revenue of $1.2 billion.

Cactus Ransomware Emergence

Cactus ransomware emerged in March of 2023 and has been steadily ramping up its attack volume through the end of 2023. Cactus is noted for its ability to evade security tools and leverage exploits for known vulnerabilities in common VPN appliances to gain initial access to the networks of targeted organizations. Cactus operators also have been observed running a batch script that unhooks common security tools.

Cactus is a new arrival on the RaaS (Ransomware-as-a-Service) scene but has quickly amassed a disturbing number of victims in a relatively short time, and attack volumes have escalated in the second and third quarters of 2023.

Techniques and Tactics

Cactus employs an encrypted messaging platform called TOX chat to conduct negotiations with victims. Ransom demands are assessed to be quite substantial, but an average has not been established. Cactus operations employ Living-off-the-Land techniques to abuse legitimate network tools like Event Viewer, PowerShell, Chisel, Rclone, and Scheduled Tasks and typically drop an SSH backdoor on systems for persistence and for communicating with the C2 servers.

Cactus has also been observed leveraging legitimate remote access tools like Splashtop and SuperOps RMM, along with deploying Cobalt Strike. In Q4-2023, Cactus operators were observed abusing Qlik Sense for initial access, as well as ManageEngine UEMS and AnyDesk for remote access and lateral movement on targeted networks.

Unique Characteristics of Cactus Ransomware

Cactus is unique in that the ransomware payload is encrypted and requires a key to execute to prevent it from being detected by security tools. It is also assessed that Cactus uses a PowerShell script dubbed TotalExec to automate the encryption process in a manner similar to the BlackBasta gang and that they attempt to dump LSASS credentials for future privilege escalation.

Cactus has been observed abusing SoftPerfect Network Scanner to do reconnaissance on prospective victims, who are generally large-scale commercial organizations across multiple sectors.