In the gaming community, these types of files are often associated with "GFX Tools" or game modifications designed to unlock higher graphics settings (like 60 FPS), reduce lag, or provide unfair advantages like "Auto Headshot" or "Wallhacks."
Navigate to your game's installation directory (e.g., C:\Program Files (x86)\Steam\steamapps\common\Call of Duty Modern Warfare 2 ). Open the zone folder.