The big banks are staying tight-lipped about it, but multiple sources say several major US financial firms were hit by hackers who made off with gigabytes of data earlier this month. The banks included JPMorgan Chase and at least four others, according to New York Times sources, who say the stolen data included checking and savings account information and the motivation of the attackers is still unclear. An FBI spokesman says the agency is working with the Secret Service to investigate the reported attacks, Reuters reports. A JPMorgan spokeswoman says "companies of our size unfortunately experience cyberattacks nearly every day" and the bank has "multiple layers of defense."
The cyberattackers were Russian, sources close to the investigation tell Bloomberg, and the FBI suspects the raid was revenge for US sanctions. The sources say the highly sophisticated attacks may be linked to recent attacks on financial firms in European countries that have also imposed sanctions on Moscow. "Russia has a policy of reactionary attacks in relation to political contexts," an analyst at cybersecurity firm iSight says. "When it comes to countries outside their sphere of influence, those attacks would be more surreptitious." (Read more cybercrime stories.)