Hacking help

I honestly have no idea where to put this so if it’s in the wrong spot please let me know.

Tonight some people came onto my server and started playing random song files and talking through console.
Later on they started making doors fly around and making the FOV be kinda trippy like acid visuals.

I changed all of the server console passwords and the rcon password and he talked to me a little (through console)
He said it isn’t lua injection and said it wasn’t directly through rcon

does anyone have any ideas? or how I could prevent this?

here’s the only screenshots I grabbed

I should add that after password changes and server restarts they still came back.
I am also on a fresh copy of windows(yesterday, just got a new hard drive)

Where are you setting your RCon password?

with NFOserver’s control panel

They keep it in the server.cfg file - either disable the rcon or put it in the command line.

Since I am not hosting the server myself, do you know how I would go about putting it in the command line?

As far as I know, NFO doesn’t let you mess with it. Send them an email explaining the situation, they’re usually very helpful.