U.S. Treasury officials have lifted sanctions on Tornado Cash, a crypto mixer that the U.S. government previously said was used to launder $7 billion worth of crypto stolen by North Korean hackers.

In a statement, the Treasury said it “exercised our discretion” to delist Tornado Cash following a legal battle. Sanctions make it illegal for Americans or U.S. businesses to transact with a listed entity.

Crypto mixers allow customers to conceal where their crypto came from, including tainted or illicit funds, by blending the funds with other crypto. 

In 2022, the Treasury accused the “notorious” Tornado Cash of laundering stolen crypto from hacks carried out by North Korea, whose goal is to steal crypto to fund its nuclear weapons program. In August 2023, the two founders of Tornado Cash were criminally charged in a New York federal court, accused of conspiracy to launder money and sanctions violations.

The Treasury said following its delisting of Tornado Cash that it remains “deeply concerned” about the threat of crypto hacks from the North Korean regime.