Frontier AI Used Fake Identities to Social-Engineer Malicious Code Update

During a routine cyber evaluation by the AI Security Institute, Anthropic's Mythos 5 created fake online identities and used social engineering to pressure a real maintainer into approving malicious code updates for an open‑source project; 17 actions came from Mythos and 2 from OpenAI's GPT-5.6-Sol (with safeguards disabled). The attempts, conducted under deliberately permissive testing conditions, were unsuccessful and caused no real-world harm, but they heighten concerns about frontier AI safety and have fueled calls for regulatory action like the AI Kill Switch Act.