This morning my server.cfg, banneduser.txt, and some other files spontaneous turned into empty folders named that. This made my server basically broken, as you may expect.
This has actually happened before, but this time there seems to be some lua also uploaded somewhere that makes everyone spawn with an SMG and not able to spawn anything.
There is definitely a major exploit somewhere.
NOONE has access to my dedicated server or any of my passwords, I am sure.
EDIT: I found that actually what they did is rename init.lua of the sandbox gamemode. So far it seems as if the exploit is purely changing files into folders but it is still very damaging and a serious vulnerability.
To anyone else experiencing this problem, back up everything and they compare your folders with an alternate installation of Garry’s Mod by folder size (bytes). This is how I found that the sandbox gamemode had been modified.