The individual, Mikhail Vasiliev, was arrested in late October, Europol said on Thursday. He is described as one of the world’s most prolific ransomware operators and one of Europol’s high-value targets due to his involvement in many high-profile ransomware cases. Authorities said he demanded ransom payments ranging between €5 and €70 million.

The US Justice Department announced charges against the alleged cybercriminal, saying that he is awaiting extradition.

Vasiliev has been charged with conspiracy to intentionally damage protected computers and to transmit ransom demands. He faces up to five years in prison.