China's star AI labs routed user requests to Claude at least 35 million times in the summer: Anthropic

Anthropic accused top Chinese AI labs, like Moonshot AI, of large-scale distillation attacks.

CFOTO/Future Publishing via Getty Images Anthropic said China's top AI labs carried out millions of distillation attacks on Claude.

It said Alibaba, Moonshot, Zhipu, DeepSeek, and Xiaomi all tried to use Claude to train their models.

In response, Anthropic is beefing up its guardrails against these attacks.

Anthropic said the top Chinese AI labs bombarded Claude with millions of distillation attacks over the summer.

The AI lab said in a Thursday report that Alibaba, Moonshot, DeepSeek, Zhipu, and Xiaomi combined launched nearly 190 million distillation attacks against Claude between May and July.

Distillation attacks refer to using the outputs of advanced frontier AI models to train and improve the capabilities of less advanced models.

Anthropic said that DeepSeek and Moonshot AI fed their users' requests into Claude rather than their own models.

It said it had recorded 23 million of such reroutings by Moonshot between May and July, and 12.1 million by DeepSeek over 14 days in July.

Anthropic also said that some of these requests — intended for Chinese AI models but routed to Claude instead — exposed sensitive data from the Chinese and Russian governments and militaries.

This included CCTV footage uploaded by a PLA-affiliated Kimi user and information on a Russian government database submitted by a Russian military contractor.

Per the report, Alibaba ran the largest attack Anthropic had ever measured, recording over 151 million exchanges between May and July carried out by 3,500 fraudulent accounts.

The accounts made Claude write out its reasoning processes, which were used to train its Qwen models, Anthropic said.

Anthropic accused Z.ai — which made headlines recently for its mysterious Ox Alpha model — of launching an attack similar in nature to Alibaba's.