A Russian man pleaded guilty in the U.S. on Tuesday to a major role in a computer hacking scheme that authorities say involved stealing and selling 160 million credit and debit card numbers.

Vladimir Drinkman faces up to 35 years in federal prison plus millions in fines and restitution when he's sentenced Jan. 15. He will be deported after he finishes his sentence in a case that U.S. Attorney Paul Fishman said in 2013 was the largest hacking and data breach scheme ever prosecuted in the country.

Drinkman, 34, wore jeans and a T-shirt to a sentencing in a nearly empty courtroom in U.S. District Court. He quietly told the judge he didn't need an interpreter to help him answer questions because he'd had a lot of practice with English the last few years, which he spent in a federal detention center in Newark awaiting trial.

He pleaded guilty to two criminal counts: conspiracy to commit unauthorized access of protected computers and conspiracy to commit wire fraud. Nine other charges were dropped. After the proceeding, lawyer Florian Meidel would not say why he pleaded now or whether the plea deal included an agreement to help the government prosecute other suspects in the case.

He admitted that from 2005 until 2012, he participated in a scheme to send malware to corporate computers to obtain personal information such as credit card numbers and then removed the malware in an effort to keep the companies from realizing they'd been attacked.

Several companies were invaded, but the biggest target was Heartland Payment Systems Inc., a Princeton-based company that processes credit cards for small and medium-sized businesses. Authorities said 130 million card numbers were stolen from there.

The information was sold to people who used it to create magnetic strips for counterfeit credit cards.

The case built on a 2009 case against Albert Gonzalez of Miami, who is serving a 20-year prison sentence. In the Gonzalez prosecution, Drinkman was listed as one of two unnamed suspects.

Drinkman, who is from Syktyvkar, Russia, and Moscow, was arrested in the Netherlands in 2012, then extradited to the U.S. the next year.

His lawyer said he'd never been to the country before.

Three defendants in the case have not been arrested and are still being sought. They are Aleksander Kalinin, of St. Petersburg, Russia; Roman Kotov, of Moscow; and Mikhail Rytikov, of Odessa, Ukraine.

Dmitriy Smilianets of Moscow is in custody in the U.S. He faces other charges in New York, including allegations he hacked into the Nasdaq stock exchange. Officials say the trading platform was not affected.