An indictment unsealed on Wednesday in federal court in Brooklyn charged Denis Gennadievich Kulkov with four counts of fraud, computer intrusion and money laundering conspiracy for operating Try2Check, which allegedly helped cybercriminals determine whether the credit card numbers they bought were valid and active.

Try2Check processed tens of millions of credit card numbers each year, according to federal prosecutors in Brooklyn.

“Today is a bad day for criminals who relied on the defendant’s platform,” Breon Peace, the US attorney for the Eastern District of New York, said in a statement.

Another $1-million was being offered for information identifying other key leaders in the group, the State Department said in a statement.

(Reporting by Washington newsroom; Additional reporting by Luc Cohen in New York.)