[The gamemode is not available anymore]
"Survival Mode" it's a 4v2 gamemode in which 4 people play as counter terrorists and 2 people play as zombies.

Survival Mode button
Objective[]
The goal fo the counter terrorists is to survive 5 minutes while the goal of the zombies is to kill all counter terrorists.
Only zombies can respawn. Zombies only have a melee attack which does about 25 damage per hit. Zombies have only 60 HP
Map[]
This mode is only playable on the map Rust Halloween.

Ilustrative Photo