[Konstantinos]

First of all, always upload the .amx file. Use Anti-DeAMX, get the ip (from bind line in server.cfg) and if it's not the same with the one you have written to your mode, exit the mode.

Last one, if someone uses your file you can make a secret command that bans everyone on his server and exit the mode as well. Let them search what is going on for days/months!