Many assume Valve Anti-Cheat (VAC) is dead for CS 1.6. VAC still runs on Steam-protected servers. Modifying core CVars via cheats or unusual CFGs will trigger a VAC ban, which permanently marks your Steam account. This ban is visible to all other games in your library.
According to a 2020 analysis by an infosec researcher on banned CS 1.6 forums, cs 1.6 wallhack cfg
cl_wallhack 1 noclip 1 r_drawsoliditems 0 r_drawworld 1 r_visuals 1 Many assume Valve Anti-Cheat (VAC) is dead for CS 1