Quick NIX Secure Script
Quick NIX Secure Script can be used during boot up, cron, bootstrapping, kickstart, jumpstart and during other system deployments.
Bro is an effective network analysis framework. It focuses on network security monitoring, Bro provides a comprehensive platform for more general network traffic analysis as well.
Lynis is an open source security auditing tool. It is used by system administrators, security professionals, and auditors, to evaluate the security defenses of their Linux and Unix-based systems.