A European man has been sentenced to 11 years in prison for his role in a scheme that stole more than $9.4 million from a credit card processor in 12 hours, the U.S. Attorney’s Office said Friday.

Sergei Nicolaevich Tšurikov, 30, of Tallinn, Estonia, was also ordered to pay $8.4 million in restitution and must be spend three years on supervised released, U.S. Attorney Sally Quillian Yates said. Tšurikov pleaded guilty on Sept. 11, 2012.

“A leader of one of the most sophisticated cybercrime rings in the world has been brought to justice and sentenced,” Yates said in a press release. “In just one day in 2008, an American credit card processor was hacked in perhaps one of the most sophisticated and organized computer fraud attacks ever conducted. Almost exactly one year later, the leaders of this attack were charged. This prosecution was successful because of the efforts of the victim, and unprecedented cooperation from various law enforcement agencies worldwide.”

In November 2008, Tšurikov and others obtained unauthorized access into the computer network of RBS WorldPay, what was then the U.S. payment processing division of the Royal Bank of Scotland Group PLC, located in Atlanta, according to prosecutors. The group hacked into the data encryption that was used by RBS WorldPay to protect customer data on payroll debit cards.

The hacking ring then raised the account limits on the compromised accounts and gave cashers around the world 44 counterfeit payroll debit cards, which were used to withdraw more than $9 million from more than 2,100 ATMs in at least 280 cities worldwide, Yates’ office said. Money was obtained in a span of less than 12 hours in cities in the U.S., Russia, Ukraine, Estonia, Italy, Hong Kong, Japan and Canada.

Tšurikov and another hacker monitored the fraudulent ATM withdrawals in real-time from within the computer systems of RBS WorldPay, according to investigators.

Payroll debit cards are used by various companies to pay their employees. By using a payroll debit card, employees are able to withdraw their regular salaries from an ATM.