: The Valve Anti-Cheat (VAC) system is designed to automatically detect cheats. If a cheat signature is identified, it results in a permanent ban from playing on VAC-secured servers for that game.

How to in-game through official channels.

Guides for with two-factor authentication. Valve Anti-Cheat (VAC) System - Steam Support

: Many cheats require you to disable antivirus software or modify core system files (DLLs), which leaves your entire computer vulnerable to other infections.