JPMorgan Chase and at least four other financial institutions were hacked recently in a series of coordinated attacks, and investigators believe Russian hackers were the source of the attacks, a federal law enforcement official told USA Today.  What is less clear is whether the attacks were prompted by U.S. sanctions against the Russian government.

The cyberattack resulted in the loss of sensitive data, including account information, security experts say. The FBI is working with the U.S. Secret Service to determine the scope of these incidents.