Dive Brief:

• The Federal Bureau of Investigation late Monday sent a detailed five-page letter to American businesses warning them that the malware behind a massive breach at Sony Pictures Entertainment is an unprecedented cyber-event involving geopolitics.

• The malware overrides the data on hard drives and prevents a reboot, making it difficult, expensive, and maybe even impossible to recover data using “standard forensic methods,” the warning said.

• The Nov. 24 attack on Sony, which has called in an elite team of security experts and is working with the FBI and the Department of Homeland Security, crippled the company’s email system and computer network and leaked some of its latest movie releases.

Dive Insight:

It was bad enough when old-fashioned thieves were the ones attacking retailers and other businesses to sell credit-card data. Now it appears that geopolitics and revenge may also be in the mix. The problem is extremely serious and has the U.S. government, law enforcement, and businesses on high alert. The cyber attack on Sony Pictures has been severe - the L.A. Times notes that many employees at the company have been working with pen and paper because their computer system is out of commission. ​

Although the FBI in its letter says the attackers are unknown, there has been speculation that the malware was the work of hackers acting on behalf of North Korea. Sony is set to release a movie, The Interview, which makes light of the possible killing of North Korean leader Kim Jong-un.