Anthropic accuses DeepSeek, Moonshot and MiniMax of distillation attacks on

Anthropic on Monday accused three Chinese AI companies of coordinated campaigns to extract information from its model, making it the latest American tech firm to level such claims after OpenAI issued similar complaints.

According to a statement from Anthropic, DeepSeek, Moonshot AI and MiniMax — the three firms in question — engaged in concerted “distillation attack” campaigns, flooding Claude with large volumes of specially-crafted prompts to train proprietary models.

Through distillation, smaller AI models can mimic the performance of larger, pre-trained models by extracting knowledge from the better-trained model, a technique particularly useful for smaller teams with fewer resources.

Despite Anthropic’s service restrictions preventing commercial access to Claude in China, the three firms allegedly engaged commercial proxy services to sidestep Anthropic’s restrictions, enabling access to networks running tens of thousands of Claude accounts simultaneously.

“Once access is secured, the labs generate large volumes of carefully crafted prompts designed to extract specific capabilities from the model,” Anthropic said in the statement.

Claude’s responses to these prompts are farmed en masse either for direct training of the Chinese models or for a process known as reinforcement learning, a data-intensive approach in which AI models learn decision-making through trial and error in the absence of human guidance.

Anthropic estimated that the three Chinese firms collectively generated over 16 million exchanges with Claude from around 24,000 fraudulently created accounts. Of the three firms, Anthropic found that MiniMax drove the most traffic, with over 13 million exchanges.

DeepSeek, Moonshot AI and MiniMax have yet to respond to a request for comment from CNBC.

Earlier this month, Sam Altman’s OpenAI submitted an open letter to U.S. legislators, claiming to have observed activity “indicative of ongoing attempts by DeepSeek to distill frontier models of OpenAI and other US frontier labs, including through new, obfuscated methods.”

The company has flagged evidence of distillation by Chinese firms since early last year, with the launch of China’s first DeepSeek model, which users found strikingly similar to ChatGPT, the Financial Times reported in Jan. 2025, citing OpenAI insiders.

Distillation, however, is not uncommon in the industry, as Anthropic acknowledged in its Monday statement that AI firms “routinely distill their own models to create smaller, cheaper versions.”

Anthropic’s allegations are likely less about industry malpractice than about violations of its terms of service, said Lia Raquel Neves,…