FBI Says North Korea Behind Sony Hack

WASHINGTON--The Federal Bureau of Investigation said Friday evidence points to North Korea as the culprit behind a hack of Sony Pictures that led the studio to pull the movie "The Interview" out of theaters.

"The FBI now has enough information to conclude that the North Korean government is responsible for these actions," the agency said in a statement.

The public finger-pointing escalates the conflict between the two countries. Officials previously said the North Korean government had emerged as the prime suspect in the hack, which exposed embarrassing internal emails between executives. The hacking culminated in a threat of violence at movie theaters that screened the movie, which involves a plot to kill North Korean leader Kim Jong Un.

The Obama administration is considering what steps to take in response to the hack, but there are few good options, according to people involved in the discussions, in part because North Korea's regime is already very isolated from world affairs.

While the Sony hack is viewed as a national security matter given it involves a computer attack by a foreign nation against a U.S. company, it doesn't fit the definition of critical infrastructure attacks U.S. officials have previously contemplated, such as an attack against a utility company, a stock exchange, or a part of the transportation grid.

In the lengthy statement, the FBI shared some of the evidence pointing to North Korea.

An analysis of malware that deleted data on Sony computers shows similarities to other malware used previously by North Korean suspects, including lines of code, encryption algorithms, data deletion methods, and compromised networks, the FBI said.

Investigators also found "significant overlap" between the infrastructure of the Sony attack and other hacking previously linked to North Korea, including Internet protocol addresses that were part of the data deletion malware.

The FBI also found similarities to a cyberattack in March 2013 on South Korean banks and media outlets. The FBI had already concluded that this attack was carried out by North Korea.

"We are deeply concerned about the destructive nature of this attack on a private sector entity and the ordinary citizens who worked there," the statement said.

"The destructive nature of this attack, coupled with its coercive nature, sets it apart," the FBI said. "North Korea's actions were intended to inflict significant harm on a U.S. business and suppress the right of American citizens to express themselves. Such acts of intimidation fall outside the bounds of acceptable state behavior. The FBI takes seriously any attempt--whether through cyber-enabled means, threats of violence, or otherwise--to undermine the economic and social prosperity of our citizens."

Write to Devlin Barrett at [e-mail]

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