CyberSum logo
Back

Gunra Ransomware Targets Windows and Linux Systems

Cyber Security News by CyberSum.net
2 sources
Gunra ransomware, active since April 2025, poses a significant threat with its dual-platform capability, targeting both Windows and Linux systems. The Windows variant uses ChaCha8 encryption and secure random number generation, making decryption impractical. However, the Linux variant has a critical cryptographic flaw, allowing potential file recovery through brute-force attacks. Organizations must develop platform-specific threat intelligence and incident response strategies to mitigate risks effectively.

Also Read

New SesameOp Backdoor Malware Uses OpenAI API for C2

Microsoft security researchers have discovered a new backdoor malware named SesameOp that uses the OpenAI Assistants API for covert command-and-control (C2) communications. The malware, found during a July 2025 cyberattack investigation, allows attackers to gain persistent access and remotely manage compromised devices. SesameOp leverages legitimate cloud services to avoid detection, encrypts harvested information, and establishes persistence through internal web shells. Microsoft advises security teams to audit firewall logs, enable tamper protection, and monitor unauthorized connections to mitigate the impact.

By Cyber Security News by CyberSum.net