Discussions on the Steam forum have highlighted the spread of malware through the multiplayer servers of the 2009 version of Call of Duty: Modern Warfare 2, distinct from the latest edition released in September 2022.

The malware appears to be a worm exploiting certain game code vulnerabilities. This issue facilitates its propagation through lobbies and enables the execution of code on the systems of gamers while they are actively playing.

Presently, the threat seems to be confined to the PC gaming community. Although other CoD titles launched around 2009 may potentially be susceptible, there are confirmed incidents associated only with Modern Warfare 2. Recent data from SteamDB indicates that this 14-year-old game attracts up to 650 players simultaneously during peak periods.

In response, Activision has temporarily disabled the servers to conduct an investigation.

CoD Modern Warfare 2 Infected by Self-Propagating Malware, Activision Shuts Down Servers