Free penetration testing tools abound. Free, easy-to-use penetration testing tools… not as much. Free, easy-to-use, web-hosted penetration testing tools, rarer still.
I came across an excellent, web-hosted NMAP port scanning tool and I wanted to make sure I linked it here in case I needed it again in the future. Without further ado…
https://pentest-tools.com/discovery-probing/tcp-port-scanner-online-nmap
I haven’t explored the rest of the site, but the ability to quickly hit a public site and “fingerprint” the most common open ports is very very handy. I hope others find this as useful as I have! What is nice about it, is that because it is web-hosted, it requires zero setup on your own machine and quickly running scans is simple as everything is GUI’d.
I have found zenmap useful if you are looking for something locally hosted to do internal scans between machines. It isn’t quite as easy to use and I have gotten some odd results from it but it provides more flexibility, especially on windows, vs. just going to the cmd shell and running the common “ping” and “telnet” commands.
While we are on the topic of excellent, free, web-hosted tools. SSL Labs has an absolutely phenomenal SSL testing suite for checking your sites SSL security. In the wake of heartbleed, there has been a lot of attention given to SSL security. If you are a company that runs a public site or sites with SSL, I recommend you start checking them now to make sure that they are configured as well as can be.
You can access that tool here:
https://www.ssllabs.com/ssltest/analyze.html
Reference:
http://security.stackexchange.com/questions/32/what-tools-are-available-to-assess-the-security-of-a-web-application/38#38
https://pentest-tools.com/discovery-probing/tcp-port-scanner-online-nmap
https://www.ssllabs.com/ssltest/analyze.html