Linux security scanners
LUNAR (system security scanner)
LUNAR is a security scanner that runs on a Linux system or other flavors of Unix. It provides insights on what can be done to harden the system.
Lynis (audit tool and security scanner)
Security auditing tool for systems running Linux, mac OS, or Unix, to perform an in-depth health check.
YASAT (local security scanner)
YASAT describes itself as another simple stupid audit tool to test Linux systems. It has many tests for checking the security configuration of the system.