Linux.com - https://www.linux.com/news/10-open-source-security-tools-you-should-know
Open source tools can be the basis for solid security and intense learning. Here are 10 you should know about for your IT security toolkit.
In many ways, security starts with understanding the situation. For a couple of generations of IT security professionals, understanding their networks’ vulnerabilities starts with Nessus from Tenable. According to sectools.org, Nessus is the most popular vulnerability scanner and third most popular security program currently in use.