Cerber2021 Ransomware Back in Action

This report provides a technical analysis of Cerber2021 ransomware—covering a 32-bit Windows executable and a 64-bit UPX-packed Linux ELF—describing how actors exploit Confluence and GitLab vulnerabilities to deliver the ransomware, the encryption behavior (files on drives C:–Z: or Linux drives are encrypted and appended with ".locked"), use of the Crypto++ library, Tor-based payment infrastructure and ransom note, sample hashes and IOCs, and recommended mitigations (patching, backups, AV).