U.S. Banks Hit with Biggest Cyberattacks Ever

Security experts say the recent “denial of service” cyberattacks on big U.S. banks were the largest ever recorded by a wide margin. Since Sept. 19, the banking websites of Bank of America Corp. (NYSE: BAC), J.P. Morgan Chase & Co. (NYSE: JPM), Wells Fargo & Co. (NYSE: WFC), U.S. Bancorp. (NYSE: USB) and PNC Financial Services Group Inc. (NYSE: PNC) have all suffered day-long slowdowns and been at times unreachable for many customers.

It is not unusual for banks to get hit by cyberattackers and they have some of the best defenses against them. But this time the volume of traffic sent to these sites in order make then crash was unprecedented — 10 to 20 times the volume that normally seen.

Senator Joe Lieberman said in a C-SPAN interview on Wednesday that he believed the attacks were launched by Iran in response to the increasingly strong economic sanctions that the United States and its allies have put on Iranian financial institutions.

Denial of service attacks do not involve any actual hacking. No data was stolen from the banks, and their transactional systems — like their ATM networks — were unaffected. The aim of the attacks was simply to temporarily disrupt the banks’ public-facing websites. Experts warn that more such attacks may still be coming.