The Trump administration designated a Cambodian financial conglomerate as a money-laundering operation on Thursday, taking the first step to sever its access to the American financial system.

The Treasury Department said that since August 2021, the company, Huione Group, and its affiliates had laundered $4 billion for criminals, including hackers in North Korea and scammers in Southeast Asia.

“Huione Group serves as a significant node of the money laundering ecosystem,” the Treasury said in a detailed report of the company’s operations.

A New York Times investigation in March found that Huione’s group of companies were at the heart of a global money laundering network. Online scammers, who defraud victims with bogus investments or other schemes, rely on Huione and its affiliates to move money overseas while evading law enforcement authorities and banks’ anti-laundering departments.

The proposed rules represent the most significant effort to crack down on Huione, which has operated with impunity and has been linked to one of the world’s largest illicit marketplaces.

Huione did not immediately respond to requests for comment.