Activision removes AI decompiler for Call of Duty: Modern Warfare 2

Legal counsel spotted the developer’s project and took action.

With the advancement of AI technologies, “vibe coders” have started to emerge. These individuals do not write programs themselves; instead, they create software code using prompts issued to artificial intelligence. Instructions are given in ordinary human language, and the AI outputs ready-to-use code as a result.

Recently, various ports and modifications created using AI or generated entirely by it have begun appearing actively online. Some enthusiasts are already applying AI capabilities to game development. For example, a post by developer Chris First recently went viral. Using Claude Opus 5.5, he managed to create a three-dimensional game titled Fallout: New York featuring a VATS system, a working Pip-Boy computer, and other recognizable elements from the Bethesda Game Studios franchise. Lawyers soon took notice of the project and quickly shut it down.

Another company owned by Xbox has also taken action. Activision lawyers shut down a project by developer Maurice Heumann. He used generative AI to decompile Call of Duty: Modern Warfare 2 on PC, transforming machine code into human-readable text. According to him, seventeen AI agents worked on this simultaneously, operating faster than would have been possible through manual labor.

Image source: Activision

Maurice Heumann asserts that Call of Duty: Modern Warfare 2 was in a playable state and most bugs had been successfully fixed. However, a full release never happened as Activision removed the video and blocked access to the website hosting the code.

In a subsequent post, the developer admitted that one of the AI agents completely wiped his system. Since it was running on a virtual machine, no critical data was lost.

The shutdowns of Fallout: New York and the AI decompilation of Call of Duty: Modern Warfare 2 demonstrate that certain rights holders have no intention of quietly allowing such projects created using AI technologies to exist.