Lynis is an auditing tool for Unix (specialists). It scans the system and available software, to detect security issues. Beside security related information it will also scan for general system information, installed packages and configuration mistakes.

This software aims in assisting automated auditing, software patch management, vulnerability and malware scanning of Unix based systems. It can [...]

Interesting, a new arena for marketing spin and sales talk – the auctioning of exploits.
WabiSabiLabi is pushing hard for a good price for a ClamAV vulnerability and exploit that it has gotten hold of, it’s dosing it up with a good portion of spin to make it seem like the next big thing – I [...]

Since Ubuntu is getting so fantastically popular nowadays I thought this might be useful to some of you.
I personally think Ubuntu is great, the features, ease of installation, stability and especially the work they have done on things like wireless drivers make it a breeze to get up and running.
It is a pretty secure distro [...]

Damn Vulnerable Linux (DVL) is a Linux-based (modified Damn Small Linux) tool for IT-Security & IT-Anti-Security and Attack & Defense. It was initiated for training tasks during university lessons by the IITAC (International Institute for Training, Assessment, and Certification) and S²e – Secure Software Engineering in cooperation with the French Reverse Engineering Team.

Damn Vulnerable Linux [...]

I came across this while browsing, has some pretty solid stuff, goes deeper than most basic Linux security guides.
It has some good sections like this on protection against fork bombs:

Fork bombs are programs that keep creating child processes until system resources are all used, they actually aren’t remote exploits because they require a local user [...]