Two administrators of the Russia-based cryptocurrency exchange Garantex are facing criminal charges in the United States for allegedly helping hackers, ransomware groups, and terrorist organizations launder illicit funds.

Garantex, a Russian crypto exchange popular with ransomware gangs and darknet markets, has been taken down in an international law enforcement operation, according to a Friday announcement from the U.

The administrators of Garantex, Aleksej Besciokov and Aleksandr Mira Serda, allegedly knew their crypto exchange was used to launder money, according to U.S. prosecutors.