: Perhaps the most legendary "rage" cheat. It featured a spin-bot that made the user's character twirl like a top while instantly headshotting anyone on the map. MPH Aimbot

is a file containing code and data that the game loads to run. Cheaters discovered that they could "inject" their own custom DLLs into the Memory Injection

. In the 1.6 era, VAC operated on "signatures." It scanned the game’s directory for known cheat DLL files. This sparked a constant cycle: would release a new DLL. would blacklist that DLL's unique signature.