The US Federal Bureau of Investigation (FBI) has warned that hackers have used malware to launch destructive attacks against businesses in the United States, following a devastating attack on the networks of Sony Pictures Entertainment.

In a five-page confidential "flash" warning sent to businesses late on Monday and seen by Reuters, the FBI provided technical details about the malware, but did not mention the corporate victim by name. According to the advisory notice, the malware is particularly violent — over-writing data on hard drives to make them little more than bricks while also closing down networks at the same time.

A Guy