Top 10 Open Source Security Tools

During my years in IT, I’ve used many tools, some open source others commercial, but all to perform daily tasks, or troubleshoot problems. Recently I thought it may be helpful if I listed, the most influential tools that seem to pop into my life over and over again. I had a tough time limiting myself to just 10, because there are so many excellent tools out there. However the one single characteristic which stands out in my mind, over all the other tools I’ve used over the years; majority of my top 10 favourite tools are Open Source.

1. Nessus – Host Vulnerability Scanner
If you’ve ever wondered if your server hosts are improperly configured, have missing patches or simply are exploitable Nessus is your tool. This is the fastest and best tool for the job.

2. Snort – Network Intrusion Detection
This tool has been around since 1998 and is by far one of the best and most versatile network intrusion detection engines out there today. Recently voted one of the greatest pieces of Open Source software of all time.

3. Nmap – Host/Port scanning utility
Absolutely the fastest and most accurate host/port detection tools out there. Discovering network hosts or determining open ports has never been this easy.

4. OSSEC – Host Intrusion Detection
Similar to Snort network intrusion detection, however instead of monitoring network traffic, OSSEC monitors the local host. It monitors, analyzes and performs integrity checking of underlying operating system functions and applications.

5. TCPDump/Wireshark – Network packet sniffing/analysis
The best packet analysis tools. While tcpdump is command line, Wireshark offers an extensive graphical user interface. Both tools are feature rich and capable of outperforming competing tools where it counts.

6. OpenVPN – Virtual Private Network Server/Client
If you’re looking to secure a network connection across public networks, OpenVPN cannot be beat on performance and price. It rivals the best commercial VPN solutions while offering similar if not better functionality.

7. Metasploit – Penetration Testing Framework
Have you ever wanted to learn how to hack. Metasploit framework has everything you need to become a white hat hacker or penetration tester.

8. Cain & Abel – Penetration Testing toolkit
An easy to use penetration testing tool with a myriad of cool functions. Literally the Swiss army knife of hacking.

9. Backtrack – Penetration Testing Linux Distribution
Linux distribution for penetration testers. Best tools and applications installed and ready to go, all in one place.

10. Aircrack – Wireless Penetration Testing toolkit
The penetration tool for wireless networks.