Update: JPMorgan, other banks hacked, and FBI looks to Russia for culprits

JPMorgan Chase was one of at least five US banks hit by a sophisticated attack against its networks that netted the attacker large volumes of bank account data—for an unknown purpose.

Joe Mabel

The FBI is reportedly investigating whether a sophisticated attack on JPMorgan Chase and at least four other banks was the work of state-sponsored hackers from Russia. The attacks, which were detected earlier this month, netted gigabytes of checking and savings account data, according to a report by The New York Times.

Update: According to one source Ars contacted who claims to be familiar with the investigation at JPMorgan Chase, the attack on the bank stemmed from malware that infected an employee's desktop computer. It was not clear whether the malware was delivered by a web attack or by an email "phishing" attack.

In a statement sent to Ars, John Prisco, CEO of the security firm Triumfant said, "The nature of the JPMorgan breach was a persistent threat with a backdoor that enabled the attacker to enter whenever they wanted." He expressed surprise that the breach went undetected for so long, claiming that it was "fairly easy breach to detect."