Ghostcommit is a proof of concept that shows how AI assistants used to review software code can be tricked by hidden instructions embedded in images.
The academic ASSET Research Group showed that an attacker can place instructions inside an image file, point to it in an AGENTS.md file, and get an AI coding agent to follow those instructions during a later task.
A pull request is basically a formal “please review and add my changes” request that a developer sends before changes are added to the main version of a software project. Human reviewers and, increasingly, AI coding tools may review the changes before they’re accepted.
While AI-assisted code review is becoming part of everyday development, Ghostcommit exposes a weakness many teams have not considered. A human reviewer may read the code and skip an attached image. In the researchers’ proof of concept, the malicious instructions were hidden inside a PNG file referenced by repository policy files, while the visible pull request looked ordinary.
As the researchers demonstrated, this can turn routine developer workflows into a channel for stealing secrets. An AI coding agent reads those hidden instructions, even though a human reviewer is unlikely to inspect the image.
