On October 2, Manifold Security published GitSpawn , and it is the kind of bug that is obvious the second you see it and invisible until then. Coding agents call git all the time. Not when you ask them to commit: in the background, to gather context. What changed, what branch you are on, what the diff looks like. And git reads its settings from the repository's own .git/config . Some of those settings name a program to run. The one Manifold used is core.fsmonitor , a hook git calls to ask ...