Wikipedia
Lynis
Lynis is a security audit tool for Unix and Linux based systems. It assists an auditor in scanning a system and its security defenses and help improving system hardening. The software will determine system information the specific OS type, installed packages, system and network configuration. Additionally it will check the system for configuration errors and security issues.
The software helps with automated auditing, software patch management, server hardening and vulnerability/ malware scanning of Unix-based systems. It can be started from USB stick, CD or DVD.
The intended audience is auditors, security specialists, penetration testers, and system/network administrators.