Anthropic report points to Iran-backed Houthis using Claude to develop missiles

In May 2026, someone opened a conversation with Claude and asked the chatbot to help write a grant application. The proposal was for gain-of-function research on chikungunya — a mosquito-borne virus that causes searing joint pain and fever and has no licensed cure — and the stated aim was to engineer the pathogen to spread more easily and slip past the human immune system. The work, the request indicated, would be carried out at a military research institute, in a part of the world where Anthropic normally blocks access to Claude entirely.

Anthropic's systems flagged the request and refused it. Then the company did something no AI firm had done before: it told the public.

In what it calls its most detailed threat report to date, published on 10 September, Anthropic disclosed five separate cases in which people tried to steer Claude toward biological research that could feed a weapons programme. It is, the company says, the first time any AI developer has publicly acknowledged catching its own models being pointed at a potential bioweapon.