• Anthropic claims Alibaba conducted the largest known attack to illegally extract AI capabilities.
• The alleged distillation attack involved nearly 29 million exchanges with Claude using fake accounts.
• Alibaba is currently challenging its designation as a military-linked company by the Pentagon.

U.S. artificial intelligence (AI) company Anthropic has accused Alibaba of "brazenly" and "illicitly" extracting capabilities from its Claude AI model in what is termed the largest known attack of its kind. In a letter sent to U.S. Senators Tim Scott and Elizabeth Warren on June 10, Anthropic claims the campaign involved approximately 28.8 million exchanges executed by operators linked to Alibaba using around 25,000 fraudulent accounts, conducted between April 22 and June 5, 2026, according to Reuters and BBC.

The letter describes the actions as "distillation attacks," a method wherein a less capable AI model is trained using answers generated by a stronger one. This technique, according to Anthropic, serves to enable the rapid advancement of Chinese AI capabilities, particularly in drawing out the complex decision-making skills of its models, as noted by both BBC and India Times.

Anthropic fears that such attacks turn significant investment and research in U.S. AI into an advantage for geopolitical competitors. The company has urged Congress to impose penalties on entities involved in such attacks and to enhance measures to protect U.S. technological assets. This viewpoint reflects concerns echoed in previous statements regarding the activities of other Chinese companies using similar tactics, as highlighted by Reuters and BBC.

Meanwhile, in light of these allegations, Alibaba has sought legal recourse against its designation on the Pentagon's Chinese military companies list, asserting that such a label is unjustified and based on inadequate evidence. The company argues that this restriction hampers its operational capabilities and is challenging the legitimacy of the designation in court, as reported by India Times and further supported by Reuters.