The Federal Bureau of Investigation warned U.S. businesses that hackers have used malicious software to launch a destructive cyber attack in the United States, following a devastating breach last week at Sony Pictures Entertainment.
Cyber security experts said the malicious software described in the alert appeared to describe the one that affected Sony, which would mark first major destructive cyber attack waged against a company on U.S. soil.
"I believe the coordinated cyber attack with destructive payloads against a corporation in the U.S. represents a watershed event," said Tom Kellermann, chief cyber security officer with security software maker Trend Micro Inc. "Geopolitics now serves as harbingers for destructive cyber attacks."
The five-page, confidential "flash" FBI warning issued to businesses late on Monday provided some technical details about the malicious software used in the attack. It provided advice on how to respond to the malware and asked businesses to contact the FBI if they identified similar malware.
The report said the malware overrides all data on hard drives of computers, including the master boot record, which prevents them from booting up.
"The overwriting of the data files will make it extremely difficult and costly, if not impossible, to recover the data using standard forensic methods," the report said.
The document was sent to security staff at some U.S. companies in an email that asked them not to share the information.
The FBI released the document in the wake of last Monday's unprecedented attack on Sony Pictures Entertainment, which brought corporate email down for a week and crippled other systems as the company prepares to release several highly anticipated films during the holiday film season.
The FBI said it is investigating the attack with help from the Department of Homeland Security. Sony has hired FireEye Inc's Mandiant incident response team to help clean up after the attack.
