Anthropic has published a detailed threat intelligence report outlining how its Claude models were misused across cyberattacks, state-linked surveillance, weapons development, and biological research between December 2025 and August 2026. The nearly 150-page report describes five documented cases involving attempts to use Claude for research that could support biological weapons development, including one instance involving gain-of-function research on a mosquito-borne virus — all of which the company says its safety systems flagged and blocked.
The report also detailed a large-scale attempt by operators linked to a major Chinese tech firm to extract Claude’s capabilities through repeated automated queries, in what Anthropic called its largest “distillation” attack to date, along with separate cases involving Russia-linked cyber espionage and conventional weapons software development. Anthropic said it banned all accounts involved and used the findings to strengthen its safeguards — a level of public disclosure that reflects growing pressure across the AI industry to demonstrate accountability as models grow more capable and more attractive to bad actors.