According to an amended complaint filed Thursday, the hackers used a number of unlawful means to obtain customer log-in information, such as usernames and passwords, to steal millions of dollars.
The government says no wider data breaches are alleged to have occurred.
Eight people are charged in the scheme.
Customer accounts were targeted at Aon Hewitt, Automated Data Processing Inc., Citibank, E-Trade, Electronic Payments Inc., Fundtech Holdings LLC, iPayment Inc., JPMorgan Chase Bank, Nordstrom Bank, PayPal, TD Ameritrade, TIAA-CREF, USAA, Veracity Payment Solutions Inc. and the payroll arm of the U.S. Department of Defense.
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