knifebot aim speed ?

Hi, I've been having a problem for days with a player who enters with aim speed and lives all the time, but mostly with knife+ speed, I tried with an alias as I read here, but that player, i.e. it's not a player at all, it's a bot, the program doesn't detect it, it's been 5 seconds make 16 kilos, go out and come back, I also tried with resrdetector
But I banned him late, and I noticed that steam is always 0:4 or 4:1, so if anyone can help with plugins and how to ban them from entering with steam 0:4?