Eight men have been indicted on charges that they hacked into credit card processing firm RBS Worldpay, and helped steal more than $9 million in a highly coordinated heist nearly a year ago, the U.S. Justice Department said Tuesday.

The 16-count indictment, which names individuals from Estonia, Moldova and Russia, is the first major break in a case federal investigators are calling "perhaps the most sophisticated and organized computer fraud attack ever conducted."

"Today, almost exactly one year later, the leaders of this attack have been charged," said Sally Quillian Yates, acting U.S. attorney of the Northern District of Georgia, in a written statement. "This investigation has broken the back of one of the most sophisticated computer hacking rings in the world."

The men are accused of cracking the data encryption that RBS WorldPay used to protect customer data on payroll debit cards, allowing them to clone the cards. Some companies use payroll cards in lieu of paychecks by depositing employee salaries or hourly wages directly into payroll card accounts, which can then be used as debit cards at ATMs. According to the government, the hacking ring also was able to raise the daily withdrawal limits on compromised accounts.

Full story: Washington Post