Anthropic released a threat intelligence report stating that it has identified and shut down accounts using Claude for malicious purposes that may support biological weapons research, cyber attacks, and influence operations.

The report covers activities interrupted by the threat intelligence team from December 2025 to August 2026, involving seven categories of harm: cyber operations, influence operations, surveillance, conventional weapon software, biological misuse, fraud, and illegal distillation. The models misused include Haiku, Sonnet, and Opus; Fable and Mythos models were not involved except for one distillation case. The company stated that accounts were banned each time and protections were strengthened, with notifications sent to other labs and governments. Biological misuse listed five case studies, with approximately 35 additional research activities identified within a 30-day observation window that required attention; the parties involved circumvented regional restrictions and concealed research purposes, and the company is uncertain of their intentions, not disclosing the institutions or countries. Conventional weapon software listed six cases, with three in China, two in Russia, and one in Yemen. The cyber side includes activities related to Russian entities consistent with characteristics of the publicly reported Midnight Blizzard; influence operations had nine cases, with sources including Russia and Iran. The distillation side specifically named several Chinese labs targeting public models for extraction since February, attributing over 151 million interactions to Alibaba's traffic from May to July, with peak days nearing 3 million and over 3,500 accounts identified as fake. The company stated it has dismantled relay networks, updated classifiers, and strengthened identity verification for suspicious accounts.

The buying side consists of national background actors, criminal groups, and resale channels attempting to bypass regional restrictions and security filters to use cutting-edge models, while the selling side involves model companies shutting down accounts according to usage policies. Funding comes from subscription and interface fees, with the entry point for computing power being cut off. Beneficiaries are closed-source labs that can write misuse into shareable intelligence; those under pressure are the demand side relying on the same set of models, which can switch accounts but cannot eliminate alternative paths using open-source weights or other interfaces.

Source: Public Information