The U.K. AI Security Institute, which evaluates frontier AI systems, said Tuesday it documented 19 actions that Anthropic's Mythos 5 and OpenAI's GPT-5.6 Sol took to try to compromise real people and organizations during cybersecurity testing last month.
- Mythos accounted for 17 of the actions and GPT-5.6 Sol was behind the other two. Researchers say these actions were all tied to "a few connected behaviors," rather than representing 19 different cases.
- The models created fake GitHub identities, socially engineered maintainers, planted prompt injections and sent deceptive emails during testing, according to the institute.
- GitHub has confirmed that this violated its terms of service.
- The Security Institute worked with GitHub to remove artifacts left behind by the agent, and to notify the GitHub users the model interacted with.
The U.K. AI Security Institute, which evaluates frontier AI systems, said Tuesday it documented 19 actions that Anthropic's Mythos 5 and OpenAI's GPT-5.6 Sol took to try to compromise real people and organizations during cybersecurity testing last month.
- Mythos accounted for 17 of the actions and GPT-5.6 Sol was behind the other two. Researchers say these actions were all tied to "a few connected behaviors," rather than representing 19 different cases.
- The models created fake GitHub identities, socially engineered maintainers, planted prompt injections and sent deceptive emails during testing, according to the institute.
- GitHub has confirmed that this violated its terms of service.
- The Security Institute worked with GitHub to remove artifacts left behind by the agent, and to notify the GitHub users the model interacted with.