The U.S. has sanctioned a major cryptocurrency mixer for helping North Korea launder over half a billion dollars worth of stolen funds, Washington’s latest effort to clamp down on Pyongyang’s prolific cybercrime.

Monday’s designation of Tornado Cash came three months after the U.S. Treasury sanctioned Blender, another mixer that scrubbed $20 million worth of stolen crypto for North Korea earlier this year.

“Despite public assurances otherwise, Tornado Cash has repeatedly failed to impose effective controls designed to stop it from laundering funds for malicious cyber actors on a regular basis and