So again, how could one end up with a compromised package on a muse instance? Wouldn't that have to be some sophisticated supply chain attack? Nope! Muse attempted to install packages from PyPI, which caused a card to pop up on the user interface asking for me to approve connecting to PyPI. I was not watching the screen, so the request timed out. It then proceeded to raw dog a list of PyPI mirrors from its training data. It couldn't figure out how to use uv, so it then generated a wheel download script that would bypass any lockfile that validated packages by hash. It forked that to the background, forgot about it, and then proceeded to attempt to manually download the specified dependencies across a dozen or two tool calls with direct URL construction over whatever mirrors returned something.
Connecting to PyPI required explicit approval, but connecting to the mirrors didn't, and so i wouldn't have even noticed if i didn't always read the raw message stream rather than the interface output because you can never trust these things. When I stopped it and said "don't connect to random pypi mirrors wtf are you doing" it told me that two of the mirrors it tried were official PyPI mirrors and that was a normal thing to do. If I wasn't a python developer and knew already there are no official PyPI mirrors, I probably would have just accepted that.
So anyway, unless you are a user with lots of direct domain knowledge about a language packaging ecosystem who is reading the entire raw message log as it happens, muse will aggressively download random shit from the internet and execute it.