Lynis - Security auditing tool for systems running Linux, macOS, BSD, and other UNIX-based systems.
Malwarebytes Anti-Rootkit - Malwarebytes Anti-Rootkit is a rootkit removal program by the Malwarebytes best known for providing the antimalware program.
Silverback - Silverback 3
GMER - GMER is an application that detects and removes rootkits .
Chkrootkit - Chkrootkit is a Linux tool to locally check for signs of a rootkit. It contains:
Malwarebytes - Malwarebytes protects you against malware, ransomware, and other advanced online threats that have made antivirus obsolete and ineffective. Free Anti-Malware & Malware .