HTB (Hack The Box) offers a free and premium (VIP) tier for its members. It’s a great platform for learning ethical hacking (along with Try Hack Me). I promised myself that after I’d gotten through the free content that I would treat myself to VIP membership, but have yet to do so. You see, I discovered that there are unintended benefits of free membership. In addition to lots of free content including the seasons machines, there is a little known way of learning on HTB: Peer snooping.
You see, when you access a machine via a non-VIP account you are essentially sharing the (virtual) machine with other users. And when you have a foothold on a box and you are stuck on privilege escalation you can snoop on other players. You can look at who else is logged on and you can monitor what they are doing. You can see what tools, commands, CVEs, etc they are trying and can learn from them.
So next time you are trying a HTB machine and you have a foothold (a login with shell) try snooping on others that are also trying to pwn the machine. You may learn something.