Particle.news

Researchers Reveal 'Plague' Linux Backdoor That Evades Detection and Maintains SSH Access

Nextron’s findings highlight how Plague embeds into the Linux authentication stack to achieve persistence

Overview

  • Researchers traced Plague variants to 2024 through VirusTotal submissions, revealing an evolving threat that slipped past all antivirus engines and has no confirmed in-the-wild detections.
  • The backdoor installs as a PAM module that patches core authentication functions and uses hardcoded passwords to grant attackers persistent SSH access.
  • Its code uses layered obfuscation, anti-debugging measures and mimics libselinux.so.8 to avoid analysis and detection.
  • Plague sanitizes the environment by unsetting SSH-related variables and redirecting shell history to /dev/null, erasing forensic traces.
  • Compilation artifacts indicate active development across multiple distributions and GCC versions, underscoring its evolving sophistication.