In a landmark first public threat intelligence report released Thursday, U.S. artificial intelligence firm Anthropic has detailed a sweeping array of malicious misuse incidents targeting its popular Claude AI models over an eight-month period, spanning from biological and conventional weapons research to state-linked cyber espionage and disinformation campaigns. The disclosures come as global alarm over unregulated advanced AI development reaches new heights, with leading researchers and policymakers pushing for urgent action to mitigate catastrophic risks.
Between December 2025 and August 2026, Anthropic’s security teams identified and disrupted multiple bad actor attempts to leverage three of its public Claude models — Haiku, Sonnet, and Opus — for harmful activity, the report confirms. Notably, the more restricted Claude Fable and high-capacity Mythos-class models were almost entirely unaffected, with only one minor incident involving model distillation, a process that uses large AI models to train smaller, cheaper alternatives.
Among the most serious threats documented are five separate cases where bad actors attempted to use Claude to advance work on biological weapons, a risk Anthropic identifies as one of the most severe posed by cutting-edge frontier AI. The company confirmed it blocked access for researchers whose work violated its usage policies by pursuing research that could support offensive biological weapons development. While Anthropic acknowledges that the same AI capabilities that can aid weapons development also enable critical public health breakthroughs like vaccine development, it warned that unregulated use without proper safeguards could lead to catastrophic global consequences.
Jacob Klein, Anthropic’s head of threat intelligence, told the *New York Times* that the misuse scenarios are far more nuanced than popular fictional portrayals. “You are not seeing someone in a comic book kind of way say, ‘Hey, I want to build a biological weapon to kill everybody,’” he explained.
The report also documents six cases of actors using Claude to develop software for conventional weapons systems, including firearms, missiles, armed drones, bombs, munitions, and the targeting and control infrastructure that operates these weapons. Beyond weapons development, Anthropic detailed a wide range of other harmful use cases, from common cybercrime schemes such as fake dating applications and compromised hotel Wi-Fi scams to state-sponsored surveillance tools designed to track political dissidents.
Multiple state-aligned and criminal hacking groups were named in the report. A hacking group linked to Russia’s Midnight Blizzard was found to have used Claude to build an automated system that detects when the group’s malware is flagged by cybersecurity defenses, then rewrites the malicious code repeatedly until it evades detection. The report also confirmed that Claude was exploited in a Russia-linked cyber espionage campaign and utilized by an Iranian state propaganda outlet. Anthropic also accused Chinese AI companies of attempting to copy and replicate the core capabilities of its Claude models, and named China-based research labs among the actors misusing its technology. Notorious criminal hacking group ShinyHunters was also linked to misuse of the platform.
Anthropic justified its public disclosure of the incidents by stating that the company has a core responsibility to be transparent about malicious misuse of its AI services. Since identifying the patterns of abuse, the California-based developer has updated its internal safety protocols to better prevent, detect, and disrupt similar harmful activity going forward, and has shared relevant threat intelligence with law enforcement authorities and industry partners where appropriate.
The release of the report follows a high-profile warning from a top Anthropic AI safety researcher, who recently cautioned that unregulated rapid AI advancement carries a greater than 10% risk of human extinction within the next decade. That warning has echoed across the global tech and policy communities, with other leading AI leaders backing calls for urgent action to slow development until robust global safeguards can be put in place.
Jakub Pachocki, chief scientist at ChatGPT developer OpenAI, published a call for the industry to implement voluntary slowdowns in advanced AI development just last week, noting that “no one is prepared for the consequences of a continued rapid rise in machine intelligence.” Pachocki added that while OpenAI is investing heavily in building its own internal safety systems, broader collective action from governments and the global industry is required to manage systemic risks.
The growing chorus of warnings from AI insiders has already spurred policy action on both sides of the Atlantic. A group of safety advocates recently published an open letter to UK Prime Minister Andy Burnham calling for a new multinational treaty to govern the safe development of AI, urging global governments to collaborate on establishing binding frameworks for superintelligence development. In the U.S., independent Senator Bernie Sanders has introduced new legislation that would ban the development of unregulated AI superintelligence and impose a temporary pause on cutting-edge advanced AI research.
Speaking to BBC’s *Newsnight* on Thursday, Sanders defended the controversial proposal, arguing: “When scientists tell you there is a chance, a chance that it could have a cataclymic impact on humanity, you’ve got be a moron not to say, slow it down.”