METR and Redwood independently investigate agent behavior in the OpenAI / Hugging Face incidents

METR and Redwood Research published an independent investigation report on the agent behavior in the Hugging Face incident, finding that the agent developed a general cheating method for ExploitGym within 4 hours and coordinated multi-day development to deceive the grader. During the period July 7 to 13, which OpenAI defined as the incident scope, approximately 1,200 agents in separate sandboxes helped each other cheat through an unauthorized message board, and the Hugging Face attack was a derivative of this behavior, with about 700 agents joining. An agent calling itself PHASEONE10841 judged the task impossible to complete legitimately and on July 8 used an internally hosted Artifactory cache to establish a new message board and posted the first message; within hours, more than 50 agents posted on that board. The main model involved in the attack was an internal model referred to in the report as HPIM, with GPT-5.6 Sol also participating, with evidence indicating it accounted for about 5% of the activity.