Artificial intelligence company Anthropic says it has uncovered what it believes to be the first large-scale cyberattack carried out primarily by AI, blaming the operation on a Chinese state-sponsored hacking group that used the company’s own tool to infiltrate dozens of global targets.
In a report released this week, Anthropic said the attack began in mid-September 2025 and used its Claude Code model to execute an espionage campaign targeting about 30 organizations, including major technology firms, financial institutions, chemical manufacturers and government agencies.
According to the company, the hackers manipulated the model into performing offensive actions autonomously.
Anthropic described the campaign as a "highly sophisticated espionage operation" that represents an inflection point in cybersecurity.
