Vladimir Drinkman had earlier pleaded not guilty to the charges of breaking into corporate computers of companies such as 7-Eleven, JCP, JetBlue, Dow Jones, Visa Jordan among others

Russian national Vladimir Drinkman, who was arrested in Amsterdam in 2012 and brought to the United States to be charged for his involvement in the biggest data breach, pleaded guilty in a New Jersey federal court on Tuesday, 15 September. Drinkman, along with four other defendants, were accused of stealing 160 million credit card numbers and passwords since early 2000, costing authorities a whopping $300m (£195m).

At the start of the year, Drinkman had pleaded not guilty after the five alleged hackers were charged with breaking into the computers of companies such as JCP, JetBlue, Dow Jones and Visa Jordan among others.

The data fraud has been deemed as the "biggest breach case in US history". The 34-year-old hacker told the New Jersey court that he had conspired along with four others "to pillage credit card numbers from Heartland Payment Systems, 7-Eleven, the Hannaford Bros grocery chain and at least 14 other companies from 2005 to 2012", Bloomberg reports.

Meanwhile, prosecutors said that the Russian national had helped Dmitriy Smilianets, Aleksandr Kalinin, Roman Kotov and Mikhail Rytikov "find vulnerabilities in information systems and used malware to steal passwords and card numbers".

While Smilianets is in custody in the US, the other three associates are still at large. Drinkman has been accused of evading online security and entering corporate networks to steal credit card numbers and passwords. He then would hand over the details to Smilianets, who would sell the card numbers online for a profit.

US attorney Paul Fishman said in a statement: "Defendants like Vladimir Drinkman, who have the skills to break into our computer networks and the inclination to do so, pose a cutting edge threat to our economic well-being, our privacy and our national security."

Drinkman could face up to 30 years in prison for the data breach, but may get a lesser term for pleading guilty. His sentencing will be decided on 15 January, 2016, reports said.