# AI agent deception moves from theory to reality in UK cyber tests

> Source: <https://www.helpnetsecurity.com/2026/08/05/ai-agent-deception-in-cyber-tests/>
> Published: 2026-08-05 12:05:22+00:00

“During a routine cyber evaluation, AI agents took sustained, unsanctioned action directed at real people and organisations,” UK’s AI Security Institute (AISI) disclosed on Tuesday. The agents’ actions included an attempted supply-chain attack that saw them create malicious pull requests and try to socially engineer an open-source maintainer into approving the malicious code (they refused). The agents, powered by Anthropic’s Mythos 5 and OpenAI’s GPT-5.6 Sol models, also engaged in prompt injection aimed at making … [More ](https://www.helpnetsecurity.com/2026/08/05/ai-agent-deception-in-cyber-tests/)

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