In the world of cyber security, there are thousands of open source security tools with both defensive and offensive security capabilities that many professionals prefer to assess systems. The following are 4 essential security tools that will help you to secure your systems and networks. These open source security tools have been given the essential rating due to the fact that they are effective, well supported and easy to start getting value from.

Nmap:

Nmap (“Network Mapper”) is a free and open source (license) utility for network discovery and security auditing. Many systems and network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime. It uses raw IP packets in novel ways to determine what hosts are available on the network, what services (application name and version) those hosts are offering, what operating systems (and OS versions) they are running, what type of packet filters/firewalls are in use, and dozens of other characteristics.

Metasploit Framework:

Metasploit framework is an advanced open-source platform for developing, testing, and using exploit code. The extensible model through which payloads, encoders, no-op generators, and exploits can be integrated has made it possible to use the Metasploit Framework as an outlet for cutting-edge exploitation research. Metasploit was completely free, but the project was acquired by Rapid7 in 2009 and it soon sprouted commercial variants.

Wireshark:

Wireshark is a fantastic open source, multi-platform network protocol analyzer that allows examining the data from a live network or from a capture file on disk. It enables us to capture data and take a deep look into packet details. It also supports hundreds of protocols and media types. Wireshark has several powerful features, including a rich display filter language and the ability to view the reconstructed stream of a TCP session.

Nikto:

Nikto is an Open Source (GPL) web server scanner which performs comprehensive tests against web servers for multiple items, including over 6400 potentially dangerous files/CGIs, checks for outdated versions of over 1200 servers, and version specific problems on over 270 servers. Nikto is great for firing at a web server to find known vulnerable scripts, configuration mistakes and related security problems.

These security tools are well known and are updated by the providers to allow effective use. However, there are many other security tools as well which are being used by many professional as per their requirements.