(CBS News) It may be the largest bank robbery in history: A crime ring is accused of stealing $45 million from financial institutions from around the world.
But these criminals weren't wearing masks or waving guns. They were armed with computers.
The case by the U.S. Secret Service is being prosecuted by the U.S. attorney for the Eastern District of New York in Brooklyn, Loretta Lynch. Seven alleged members of the New York cell of this global cyber-crime operation have been arrested, CBS News senior correspondent John Miller reported on "CBS This Morning."
Miller, a former FBI assistant director, reported, "We've learned how they carried out this cyber-attack, and it's unlike anything ever seen before."
They call it the "unlimited operation," in which its associates - hundreds of them - were spread all over the world, and they targeted at least 26 countries. They struck twice, first in December, when they hacked into an Indian bank, and then withdrew money from ATMs all over the world, totaling $5 million. The second strike occurred in February. The hack targeted a Visa and MasterCard processor in the U.S. The loss this time totaled approximately $40 million.
Miller explained, "You know, this is- if you're a criminal, this is a gorgeous scheme. If you are a bank, this is your worst nightmare. And if you're a prosecutor like Loretta Lynch or the Secret Service agents involved in this case, it's a great caper, in terms of the case, but you realize you're just at the tip of the iceberg.
"What you have here is you've got backers. These are people who have got big money who are paying people to break into the bank systems, get the PIN numbers of debit card accounts and so on - those are the hackers. So the backers pay the hackers. Then you go to the cashers, and the cashers- once the backers have paid the hackers they've broken through, they've now gotten the PIN codes and they've raised the limits on the accounts to be unlimited for withdrawal, the cashers go out. When they get the PIN numbers and the signals on their smartphones, they're told 'go.' In the case in New York, the New York cell went up and down Broadway and in the course of two hours took $2.8 million out of ATMs from 116th Street to 23rd Street in a line."
The New York cell probably contained a dozen people, Miller said, adding, "But remember, there's 26 countries with a dozen people in each one of those countries who now have the codes and keep banging the machines until the machine runs out of money."
And this may be just the beginning, Miller said. "What you've got is surgical precision by the hackers to actually get through the bank firewalls, get administrative rights in their system, raise the limits. You've got the global nature of the organization, which is, you know, it may be based in the Middle East. Those are the kinds of banks they're targeting. But certainly they've got a global network of trusted associates who can do this. And, of course, the speed and coordination of the attacks. By the time it's almost over is when the bank is just figuring it out."
Watch Miller's full report and analysis in the video above.