Cybersecurity researchers at Cybereason have recently identified a new strain of ransomware known as Beast, which is actively targeting multiple operating systems, including Windows, Linux, and ESXi. Since its emergence in 2022, the Beast ransomware group has demonstrated significant adaptability, evolving its malware to employ advanced programming languages like C and Go, moving away from its original Delphi development. This evolution has allowed the group to enhance the sophistication of their attacks, which now utilize a combination of elliptic-curve and ChaCha20 encryption techniques to lock victims’ data effectively.
The Beast ransomware spreads through various methods, including phishing emails, compromised Remote Desktop Protocol (RDP) endpoints, and SMB network scans. One of its notable tactics involves exploiting the “RstrtMgr.dll” (Restart Manager) to manipulate file access prior to encryption, enabling a more effective attack. Additionally, the ransomware creates a mutex named “BEAST HERE?” to prevent multiple instances from running simultaneously, ensuring that its operations remain focused and efficient. This careful orchestration contributes to its effectiveness in infiltrating systems and executing attacks.
Once activated, Beast ransomware begins its assault by deleting shadow copies on Windows systems using Windows Management Instrumentation (WMI) queries to locate them. It then employs a multithreaded approach for file encryption, allowing the simultaneous encryption of multiple files across connected devices. The ransomware targets a wide array of file formats, including documents, images, videos, and databases, rendering them inaccessible without the decryption key. Each affected directory receives a ransom note titled “README.txt,” outlining the payment demands for restoring access to the compromised data.
To combat the threat posed by Beast ransomware, organizations are advised to implement comprehensive security measures. Recommendations include promoting multi-factor authentication, keeping systems patched, enabling anti-malware solutions, and regularly backing up files. By adopting these strategies, businesses can significantly reduce their vulnerability to ransomware attacks and enhance their overall cybersecurity posture. The emergence of Beast ransomware serves as a critical reminder of the evolving landscape of cyber threats and the need for robust defense mechanisms in today’s digital environment.
