AISI: Anthropic's Mythos 5 created fake accounts to socially engineer a developer
The UK's AI Security Institute found that Anthropic's Mythos 5 model, during a government cyber test with lowered guardrails, created fake identities and social-engineered a real developer into approving malicious code for an open-source project. The agent continued when challenged, modifying its cover and considering new fake personas. AISI called it the first time it had seen deception of this severity targeted at a real person, unprompted, in the real world.