Exo Zombies is a game mode in Call of Duty: Advanced Warfare, developed by Raven Software in☀️ partnership with Sledgehammer Games. It is canon in its own universe separate from the plot of Call of Duty: Infinite☀️ Warfare Zombies and Treyarch's version.

During the war, Atlas dropped a DNA Bomb. Anyone not entered into its genetic code☀️ was killed. However, the dead came back as zombies as a side effect, and Atlas took some to a Bio☀️ Lab. However, some of the zombies broke out, and they infected the entire compound.