washington - U.S. law enforcement officials have charged a Russian national with running Try2Check, a network of websites that verified stolen credit card numbers for cybercriminals.

The network's four websites have been taken offline, and the State Department announced a $10 million reward for information leading to the capture of Denis Gennadievich Kulkov, the alleged mastermind of Try2Check.

Kulkov is believed to live in Samara, Russia.

A grand jury indictment unsealed on Wednesday charges him with access device fraud, computer intrusion and money laundering.

If convicted, he could face up to 20 years in prison.

Breon Peace, United States attorney for the Eastern District of New York, and Patrick Freaney, special agent-in-charge of the U.S. Secret Service's New York field office, announced the charges.

"Today is a bad day for criminals who relied on the defendant's platform as the gold standard to verify that the credit cards they stole from hard working individuals living in the Eastern District of New York and across the world had value," Peace said in a statement.

According to court documents, Kulkov created Try2Check in 2005, and he developed it into a critical online service for cybercriminals buying and selling stolen credit cards.

Cybercriminals steal millions of credit card numbers every year by hacking into corporate databases and payment systems. They then sell the numbers in batches of thousands or even millions through online message boards known as "carding forums." But many of the numbers are worthless because they're either inactive or deactivated.

To weed out the bad numbers, cybercriminals use "card checking" websites such as Try2Check.

These services allow cybercriminals to verify the authenticity of the stolen credit card numbers before selling them.

Try2Check was one of the most popular services of its kind, processing tens of millions of checks per year through its four separate websites, according to court documents.

On carding forums, cybercriminals offering stolen cards sometimes included a screenshot of a verification report produced by Try2Check, according to court documents.

Try2Check charged the equivalent of 14 cents in bitcoin per check, earning Kulkov at least $18 million.

The FBI and U.S. Secret Service had been investigating Try2Check since 2013, according to court documents.

The takedown was coordinated with law enforcement in Austria and Germany.

Credit card fraud is a growing problem worldwide.

The Nilson Report estimates that global losses from card fraud will exceed $397 billion over the next 10 years, including $165 billion in the United States.