Anthropic—Anthropic disclosed blocking state-linked actors' attempts to use Claude for bioweapons research, cyberattacks, and surveillance

On September 10, 2026, Anthropic published a threat intelligence report covering December 2025-August 2026 disclosing that it detected and blocked misuse of Claude models by state-linked and criminal actors. This included five case studies of attempts to use Claude in ways that could support biological weapons development (involving chikungunya, avian influenza, smallpox, and animal toxins), including a request from an actor affiliated with an unidentified military institution seeking help with a chikungunya research proposal that could have made the virus more dangerous. The report also identified Russia-linked cyber-espionage group GTG-20006 (linked to Midnight Blizzard), Chinese state-linked activity, and Yemen-based arms manufacturers using Claude for conventional weapons development, plus fraud, influence operations, and surveillance-tool cases. Anthropic said users in Russia, China, and Iran circumvented geographic restrictions via fraudulent accounts and resellers, and acknowledged that safeguards on older models (Haiku, Sonnet, Opus) were less stringent than on newer ones, cautioning it could not always determine whether flagged research was legitimate or nefarious.