New Undectable Plague Malware Attacking Linux Servers to Gain Persistent SSH Access

**Plague** is a sophisticated Linux backdoor that subverts PAM authentication to provide persistent, covert SSH access, using evolving string obfuscation, anti-debug checks, hardcoded backdoor credentials, and session sanitization to evade detection; multiple samples compiled across 2024–2025 and submitted to VirusTotal exhibited 0/66 AV detections, and the report includes SHA-256 IoCs and mitigation recommendations to audit PAM modules and monitor authentication subsystems.