A Visa spokesman said the company does not comment on private internal communications regarding an ongoing investigation.
Meanwhile, in a blog post Monday, Krebs added that he has information suggesting that Global Payments may have been breached for much longer than the company has let on. According to Krebs, documents obtained from a hacker suggest that criminals may have had control of the company's network for the past 13 months before they were discovered earlier this year. Krebs claimed that document, which he is attempting to authenticate with Global Payments, appears to contain sensitive information about the payment processor's internal databases.
Amy Corn, a spokeswoman with Global Payments, would neither confirm no deny whether Track 1 data had been compromised in the breach. "What I can tell you is that the investigation to date has shown that cardholder names, addresses and Social Security numbers," were not exposed, she said, reiterating earlier comments by the company.
According to Litan, some in the payment industry believe that the breach will "mushroom." Global Payments has said that no merchant system was involved, but Litan said her sources have indicated that the breach may involve a taxi and parking garage company in the New York City area, although that is still unconfirmed. She noted that Global Payments is not obligated to report the breach publicly if cardholder names and other personally identifying information was not exposed.
In a blog post on the Gartner site, Litan said she has information suggesting that the crime was perpetrated by a Central American gang "that broke into the company's system by answering the application's knowledge based authentication questions correctly. Looks like the hackers took over an administrative account that was not protected sufficiently," Litan said.
Corn said she couldn't confirm or deny Litan's claim that a NYC cab company might have been involved in the breach. She also offered no comment on Krebs' latest post suggesting the company's networks may have been under criminal control for more than a year.
Adam Bosnian, executive vice president of security vendor Cyber-Ark, said that if Litan's information about how the breach occurred is correct, it would fit into a developing pattern.
"Targeting privileged accounts as a gateway to an organization's high value targets is becoming a startling trend," Bosnian said. " If you examine the rash of recent breaches, they follow a distinct pattern. Hackers gain access to an administrative account through often-simple means, like an easy-to-crack password, spear-phishing or exploitable zero-day vulnerability," and then escalate their privileges on the compromised computer.
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