Proving Grounds is another great platform that is used to learn pentesting and is created by Offsec. This platform allows for people to practice their penetration testing skills on vulnerable machines. This platform allows you to start up a virtual machine instance (and even a Kali instance if you need it, otherwise they provide a VPN) to create a secure environment for you to test in. These vulnerable machines are live and are secure from the internet so you do not have to worry about it being on your network. For my purposes, I VPN into the environment using my own VM. Although I have just began using this platform, I really enjoy it. For the vulnerable machines, you are able to submit a flag for both the user and root and gain points for it.

The free tier has all Linux boxes, but the premium tier has some Windows boxes mixed in that you are able to access, which makes this platform different from VulnHub. Just as a note, I will only be posting the PG play writeups and no PG practice ones. It has also been noted by Offsec that all of the boxes on Play are also available on VulnHub, although VulnHub has a larger selection.

Proving Grounds: https://portal.offsec.com/labs/play