Russian hackers attacked not only JPMorgan Chase & Co. but at least four other banks this month in a coordinated assault that resulted in the loss of gigabytes of customer data, according to two people familiar with the investigation.
At least one of the banks has linked the breach to Russian state-sponsored hackers, said one of the people. The FBI is investigating whether the attack could have been in retaliation for U.S.-imposed sanctions on Russia, said the second person, who also asked not to be identified, citing the investigation.
The attack led to the theft of account information that could be used to drain funds, according to a U.S. official and another person briefed by law enforcement who said the victims may have included European banks. Hackers also took sensitive information from employee computers.
Most thefts of financial information involve retailers or personal computers of consumers. Stealing data from big banks is rare, because they have elaborate firewalls and security systems.
JPMorgan, the biggest U.S. bank, said yesterday it took additional steps to safeguard sensitive and confidential information. The company will contact any customers who might have been affected, though it hasn't seen unusual levels of fraud, Patricia Wexler, a spokeswoman for New York-based JPMorgan, said in an email. She declined to give examples of the firm's stepped-up security.
The incidents occurred at a low point in United States-Russia relations. Russian troops continue to mass on the Ukrainian border even after the United States and European nations have hurt Russia's economy with sanctions. Russia has a history of using criminals and other proxies to hit back at adversaries in cyberspace.
Investigators have determined that the attacks were routed through computers in Latin America and other regions via servers used by Russian hackers, according to people familiar with the probe.
The Federal Bureau of Investigation is working with the U.S. Secret Service to determine the scope of "recently reported cyber attacks against several American financial institutions," J. Peter Donald, a spokesman for the FBI in New York, said in a statement.