Workers remove a poster-banner for The Interview from a billboard in Hollywood, a day after Sony announced it had no choice but to cancel the movie’s Christmas release and pull it from theatres due to a credible threat.
The US government has blamed North Korea for a devastating cyber-attack against Sony Pictures, calling it an unacceptable act of intimidation and vowing to impose “costs and consequences” on those responsible.
It was the first time the United States has directly accused another country of a cyber-attack of this nature on American soil.
The “destructive nature” of the attack, which led the big Hollywood studio to pull a movie depicting North Korea’s leader amid threats, coupled with “its coercive nature”, set it apart from previous cyber intrusions, the Federal Bureau of Investigation (FBI) said.
“As a result of our investigation, and in close collaboration with other US government departments and agencies, the FBI now has enough information to conclude that the North Korean government is responsible for these actions,” the FBI said in a statement.
“North Korea’s actions were intended to inflict significant harm on a US business and suppress the right of American citizens to express themselves,” it said. “Such acts of intimidation fall outside the bounds of acceptable state behaviour.”
“We are deeply concerned about the destructive nature of this attack on a private sector entity and the ordinary citizens who worked there,” the FBI said.
A Sony source had told AFP that the studio also believes Pyongyang was behind the attack.
“We don’t know, but it appears so,” said the source.
The attack involves the use of malware and rendered thousands of Sony Pictures computers “inoperable”, forcing the company to take its entire network offline, the FBI said.
The FBI said technical analysis of malware used in the Sony attack found links to malware that “North Korean actors” had developed and found a “significant overlap” with “other malicious cyber activity” previously linked to Pyongyang.
North Korea has previously denied involvement, and a North Korean UN diplomat on Thursday declined to comment on the accusation that Pyongyang was responsible.
“Working together, the FBI will identify, pursue, and impose costs and consequences on individuals, groups, or nation states who use cyber means to threaten the United States or US interests,” said the FBI. It stopped short of threatening specific US action.
US experts say that options for the Obama administration could include cyber retaliation, financial sanctions and even a boost in US military support to South Korea to send a stern message to North Korea.
But the effect of any response could be limited given North Korea’s isolation and the fact that it is already heavily sanctioned.
The attack on Sony more than three weeks ago, the most destructive hacking of a company on US soil, was conducted by hackers calling themselves “Guardians of Peace”.
It brought down the computer network at Sony Pictures Entertainment, prompted the leak of embarrassing e-mails, and led to Sony’s cancellation of the Christmas Day release of The Interview, a comedy film that culminates in a scene depicting the assassination of North Korean leader Kim Jong Un.
US movie theatres had said they would not show the film after hackers made threats against cinemas and audiences.
The hackers invoked the memory of September 11, 2001 in threatening attacks on cinemas screening the film.
Senior Republican lawmaker John McCain – the incoming chairman of the Senate Armed Services Committee – yesterday called the cyber-attack an “act of war”.
But the FBI statement appeared to indicate the US government was treating the incident as more of a criminal act.
“We follow the facts and evidence wherever they lead, to identify the fingers at the keyboards that threaten our people, our companies, and our national security,” said John Carlin, assistant US attorney-general for national security. “Identifying those responsible for these attacks is only the first step, and we will continue to do our part to protect and defend our nation from the asymmetric threats posed through cyberspace.”
Free speech advocates and foreign policy hawks slammed Sony’s decision to pull The Interview as cowardice in the face of a hidden enemy.
McCain said it set a “troubling precedent that will only empower and embolden bad actors to use cyber as an offensive weapon even more aggressively in the future”.
But Sony defended its decision, saying the safety of theatre patrons was at risk.
“This was a terrorist act, and you don’t take that lightly,” the company source said. “This is much bigger than us ... it’s a whole new world, now warfare is on the cyber level.”