How TeamPCP Turned a 40-Minute PyPI Window Into the Biggest AI Supply Chain Breach of 2026

A hacker group called TeamPCP poisoned a vulnerability scanner, used it to steal a PyPI publishing token, and pushed two malicious versions of LiteLLM, the open-source AI gateway with 95 million monthly downloads. The packages were live for 40 minutes. In that window, 47,000 copies were downloaded, Mercor lost 4 terabytes of data, Meta suspended its contract with the $10 billion AI data startup, and a class-action lawsuit was filed. This is the anatomy of AI infrastructure's most consequential supply chain attack.