One of my favorite tools for penetration testing is Nessus from Tenable Network Security. Nessus 5 is the latest release in the family of vulnerability scanners that is probably amongst the most prolific. Nessus 5 does discovery, configuration auditing, profiling, looks at patch management and performs vulnerability analysis on a variety of platforms. Nessus can also run on a Linux, Windows or Mac OS X and can be used to scan and keep track of vulnerabilities for practically any platform, including Mac OS X. To install Nessus, go to the Nessus site and click on the Download button, around the middle of the page. Agree to the download agreement and…