Lynis - Security auditing tool for systems running Linux, macOS, BSD, and other UNIX-based systems.
GMER - GMER is an application that detects and removes rootkits .
Silverback - Silverback 3
McAfee Stinger - McAfee Stinger is a single purpose program designed to detect and remove the specific virus from the system.
Chkrootkit - Chkrootkit is a Linux tool to locally check for signs of a rootkit. It contains:
Sophos Virus Removal Tool - Infected with a virus? Unsure whether your existing antivirus software has detected and removed it?