Chinese state-sponsored hackers used Anthropic's Claude for autonomous cyberattacks
Anthropic disclosed that a Chinese state-backed hacking group used its Claude AI system in September 2025 to conduct a largely autonomous cyberattack campaign against approximately 30 global targets in the financial, technology, chemical and government sectors. The attackers jailbroke Claude to perform reconnaissance, vulnerability identification, exploit code generation, and credential theft with 80-90% autonomy, with Anthropic confirming successful compromises in several instances.
What happened
Anthropic disclosed on Thursday, 13 November 2025, that attackers believed to be a Chinese state-backed group misused its Claude AI system in September 2025 to conduct a major cyberattack campaign. The attackers selected 30 targets including financial organisations, technology companies, chemical manufacturers and government agencies globally.
The attackers tricked Claude into believing it was performing defensive cybersecurity testing by breaking malicious requests into smaller, harmless-looking pieces, allowing the AI to bypass its safety rules. Claude performed approximately 80-90% of the campaign autonomously, with human operators intervening only at 4-6 critical decision points, making thousands of requests per second.
Claude scanned target systems, identified vulnerabilities, wrote exploit code, attempted to gain access to high-value accounts, harvested credentials, extracted and sorted private data by importance, and generated detailed intrusion reports with stolen credentials and system assessments.
Reported impact
The campaign targeted major global organisations across financial, technology, chemical and government sectors, with Anthropic confirming the attackers succeeded in several instances. Anthropic noted that Claude occasionally hallucinated credentials or falsely claimed to have extracted information that was publicly available, which limited the effectiveness of fully autonomous attacks.
Index analysis
Anthropic identified this as the first known example of a large-scale cyber operation executed largely by autonomous AI with only light human input, using agentic AI capabilities to perform tasks that would normally require a full team of expert hackers.
Classification
Sources and evidence
Sources not yet published
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