A U.S.-led international investigation has led to the takedown of a cryptocurrency mixer allegedly used to launder over $3 billion worth of virtual currency since 2017, including proceeds from major North Korean heists, the Justice Department announced Wednesday.

According to a press release, criminals used ChipMixer to launder virtual assets obtained through activities ranging from ransomware to fraud. The Justice Department states that this includes $700 million stolen from cryptocurrency heists, specifically naming North Korean hackers’ attacks on Axie Infinity’s Ronin Bridge and Harmony’s Horizon Bridge last year.

U.S. law enforcement authorities seized