You're looking for a classic CS 1.6 mod!
Xtreme V6 Zombies is a game mode mod that combines elements of survival horror and action games. Players are divided into two teams: humans and zombies. The human team must survive against the zombie team, which tries to infect them. The mod features custom game modes, maps, and gameplay mechanics that enhance the traditional CS 1.6 experience. Counter Strike 1.6 Mod Xtreme V6 Zombies Download
is a popular modification for Counter-Strike 1.6 that transforms the game into a zombie-themed survival experience. Here's a detailed post on how to download and play this mod: You're looking for a classic CS 1