The attack took less than 12 hours. While people targeted Anthropic’s servers, agents found a vulnerability in third-party office software.

A startup founded by former employees of Elon Musk’s DOGE carried it out. The agents reached sales systems and internal tools and some customer contacts, but not Claude user chats or model source code.

The work happened under Anthropic’s bug bounty program, which asked them to find vulnerabilities so they could be fixed.