Is there a plugin that detects cheaters or aimbot on the server ?

https://umod.org/plugins/logger
https://umod.org/plugins/admin-radar
https://umod.org/plugins/arkan
https://umod.org/plugins/stash-traps
https://umod.org/plugins/server-armour

You can use RustAdmin to set up rules for you server bases on existing VAC bans, game bans, rustadmin bans, etc.