GoKawiilCEO of Anthropic Dario Amodei attends a working lunch with G7 leaders, G7 outreach partners and global tech CEOs on innovation and AI, during the G7 Summit on June 17, 2026, in Évian-les-Bains, France.
Anthropic sent a letter to the U.S. Senate Committee on Banking, Housing, and Urban Affairs accusing the Chinese tech company Alibaba of "brazenly" and "illicitly" attempting to extract its artificial intelligence capabilities, CNBC confirmed on Wednesday.
The letter, which was addressed to Sen. Tim Scott, R-S.C., and Sen. Elizabeth Warren, D-Mass., on June 10, said Alibaba carried out "the largest known distillation attack on Anthropic to date."
Distillation is an AI training method where a small, less capable model is built using outputs from an existing, stronger model.
Anthropic said operators affiliated with Alibaba and its AI lab carried out 28.8 million exchanges with its models using roughly 25,000 fraudulent accounts between April 22 and June 5, according to the letter, which was viewed by CNBC.
"We believe combating the threat of illicit distillation requires coordinated action between government and industry, and we will continue working with Congress and the Administration to maintain American AI leadership," an Anthropic spokesperson said in a statement.
A representative for Alibaba did not immediately respond to CNBC's request for comment. Bloomberg was first to report the letter.