The U.S. Department of Justice said today it arrested a Ukrainian man who deployed ransomware on behalf of the REvil ransomware gang, a Russian cybercriminal collective that has extorted hundreds of millions from victim organizations. The DOJ also said it had seized $6.1 million in cryptocurrency sent to another REvil affiliate, and that the State Department is now offering up to $10 million for information leading to the arrest of any key leaders of REvil.