The Treasury continues targeting the favorite crypto mixers of North Korea’s notorious Lazarus Group.

The United States Treasury Department has barred all American citizens and entities from using Sinbad, a crypto mixer that masks the origin, destination and addresses of Bitcoin transactions. 

On Wednesday morning, the Treasury’s Office of Foreign Assets Control (OFAC) sanctioned Sinbad for being “a key money-laundering tool of the OFAC-designated Lazarus Group,” per the government’s press release.  

While the Treasury Department didn’t specify the total dollar amount laundered through Sinbad, it wrote that Sinbad was used to obfuscate “a significant portion” of stolen assets from Atomic Wallet, Axie Infinity and Horizon Bridge in 2022 and 2023. The Treasury repeated its stance that Lazarus has become a vehicle for converting crypto hacks into funds for North Korea’s ballistic missile program. 

The U.S. government has since seized the website for Sinbad. The website indicates coordination between U.S., Dutch and Finnish law enforcement. 

The recent move by the Treasury Department comes more than a year after OFAC sanctioned Tornado Cash, another crypto-mixing service that Lazarus used to mask and launder its cybercrime proceeds, including several of the same hacks it has implicated Sinbad in.

Blockchain analytics company Elliptic indicated that Sinbad is a relaunch of Blender, the first crypto-mixing service that OFAC added to its sanctions list in 2022. Specifically, Sinbad’s service wallet received bitcoin before it launched from “a wallet believed to be controlled by the operator of Blender.” Most early incoming transactions to Sinbad came from the suspected Blender operator wallet, according to Ellipitc’s analysis. 

Even though Blender was the first sanctioned crypto-mixer, the United States government has targeted other laundering services that concealed cryptocurrency transactions before. In 2021, the FBI  investigated Helix, “a Darketnet-based cryptocurrency laundering service,” and its operator Larry Dean Harmon who pleaded guilty to money laundering conspiracy

Deputy Secretary of the Treasury Wally Adeyemo said in a statement, “While we encourage responsible innovation in the digital asset ecosystem, we will not hesitate to take action against illicit actors.”