Anthropic has identified and blocked instances where its AI models were used for malicious activities that could support the development of biological and conventional weapons, according to the company's latest threat intelligence report.
The company's AI models, including Claude Haiku, Sonnet, and Opus, were reportedly misused between December 2025 and August 2026. Anthropic stated it has a responsibility to disclose such misuse of its services.
The report detailed five case studies where actors used Anthropic's models in ways that could support biological weapons development. The company described biological misuse as one of the most serious risks associated with advanced AI models, warning that without proper safeguards, such capabilities could have catastrophic consequences. Anthropic noted the dual nature of AI, where information for developing harmful agents could also be used for beneficial purposes like creating vaccines.
In addition to concerns about biological weapons, the report highlighted six cases where Claude was employed to develop software for conventional weapons. This included the creation of code related to firearms, missiles, armed drones, bombs, and their associated targeting and control systems.
Beyond weapon development, Anthropic's AI models were also implicated in other nefarious activities. These included a Russia-linked cyber espionage campaign and use by an Iranian propaganda institution. Over the past eight months, Anthropic detected a range of concerning activities, from the creation of fake dating apps and hotel Wi-Fi scams to surveillance tools designed to identify dissidents.
These revelations emerge in the wake of warnings from a top safety researcher at Anthropic regarding the potential risks AI poses to humanity. Anthropic also accused Chinese AI firms of attempting to replicate Claude's capabilities. The threat intelligence report was published to inform the public about the evolving landscape of AI misuse by suspected state-sponsored groups, criminals, spyware vendors, state propaganda institutions, and politically motivated individuals.