Mercor Data Breach Targets AI Supply Chain

### Executive summary An underground forum listing claims a 4 TB exfiltration from Mercor — a recruiting firm working with major AI companies — and Cybernews evaluated provided samples that appear credible, exposing user activity logs, proprietary prompts, credentials, and internal role assignments; Mercor has not publicly confirmed the new incident. The report also recalls a prior LiteLLM supply-chain compromise that harvested credentials, but investigators have not yet definitively linked the new advertisement to the previous breach.