Hackers broke into Citibank's network of ATMs inside 7-Eleven stores and stole customers' PIN codes, according to recent court filings that...

Share story

SAN JOSE, Calif. — Hackers broke into Citibank’s network of ATMs inside 7-Eleven stores and stole customers’ PIN codes, according to recent court filings that revealed a disturbing security hole in the most sensitive part of a banking record.

The scam netted the alleged identity thieves millions of dollars. But more importantly for consumers, it indicates criminals were able to access PINs — the numeric passwords that theoretically are among the most closely guarded elements of banking transactions — by attacking the back-end computers responsible for approving the cash withdrawals.

The case against three people in U.S. District Court for the Southern District of New York highlights a significant problem.

Hackers are targeting the ATM system’s infrastructure, which is increasingly built on Microsoft’s Windows operating system and allows machines to be remotely diagnosed and repaired over the Internet. And despite industry standards that call for protecting PINs with strong encryption — which means encoding them to cloak them to outsiders — some ATM operators apparently aren’t properly doing that. The PINs seem to be leaking while in transit between the automated teller machines and the computers that process the transactions.

It’s unclear how many Citibank customers were affected by the breach, which extended at least from October to March and was first reported by technology news Web site Wired.com. The bank has nearly 5,700 Citibank-branded ATMs inside 7-Eleven stores throughout the U.S., but it doesn’t own or operate any of them.

All that’s known is the ATM network was breached through a server at a third-party processor, which means those responsible probably didn’t have to touch the ATMs at all to pull off the heist.

The alleged plot is outlined in court papers supporting the prosecution of three people — Yuriy Rakushchynets, Ivan Biltse and Angelina Kitaeva. They were indicted in March on two counts each of conspiracy and fraud. Prosecutors say their activities generated at least $2 million in illegal profits.

Lawyers for all three did not return calls for comment, and it was unclear where they had been living. The main defendant, Rakushchynets, was described as having Michigan and Florida driver’s licenses in a February FBI affidavit for an arrest warrant.