I have an idea to help solve these GMod “viruses”.
A concommand that deletes ANY Lua and/or Dua (cache) file downloaded from the server.
Possibly the command name would be something like this:
flush_downloaded_lua
Or something like that.
Only downside is you’d have to redownload all Lua from any server you go to regularly, but meh, there’s a price for solutions sometimes.