North Korea behind Sony hacking: US
North Korea was behind the unprecedented act of cyber-warfare against Sony Pictures that drove the studio to cancel all release plans for the film at the heart of the attack, US investigators say.
The Sony hack has been connected to the isolated communist nation, according to an official.
Earlier the besieged company cancelled the Christmas Day release of The Interview, citing the threats of violence against cinemas and decisions by the largest multiplex chains in North America to pull the film from its screens. It later said there were no further plans to release the film.
The attack was possibly the costliest yet for a US company, said Avivah Litan, a cyber-security analyst at research firm Gartner. "This attack went to the heart and core of Sony's business - and succeeded," she said.
"We haven't seen any attack like this in the annals of US breach history."
The movie cancellation was a startling blow to the Hollywood studio. The hackers, who call themselves Guardians of Peace, had threatened attacks reminiscent of September 11 2001 against cinemas showing the film.
Sony then offered cinemas the option of bowing out, and one after the other, all the top US chains announced they were postponing any showings of the comedy about a pair of journalists played by James Franco and Seth Rogen tasked by the CIA to assassinate North Korea leader Kim Jong Un. Sony said it then had little choice but to cancel the release.
"We are deeply saddened at this brazen effort to suppress the distribution of a movie, and in the process do damage to our company, our employees, and the American public," Sony Pictures said.
"We stand by our film-makers and their right to free expression and are extremely disappointed by this outcome."
Just how much the hack and the decision to pull the movie will cost Sony is unclear. And beyond the financial blow, some say the attack and Sony's response has raised troubling questions about self-censorship and whether others studios and US companies are now open season for cyber-terrorists.
"Artistic freedom is at risk," said Efraim Levy, a financial analyst who covers parent company Sony Corporation for research firm S&P Capital IQ. "Are we not going to put out movies that offend some constituencies?"
In an interview with ABC News, US p resident Barack Obama said of the hacking: "The cyber-attack is very serious.
"We're investigating and we're taking it seriously. We'll be vigilant. If we see something that we think is serious and credible then we'll alert the public. But for now, my recommendation would be that people go to the movies."