U.S. investigators have determined that North Korea was behind a cyber attack on Sony Corp's computers, U.S. government sources said on Wednesday.
One of the sources described the attack as "state-sponsored" and several sources said that North Korea was the government involved.
The Obama administration was debating internally whether to make a public announcement of the investigators' findings, the officials said, speaking on condition of anonymity.
Sony Pictures earlier on Wednesday canceled the Dec. 25 theatrical release of its North Korea comedy "The Interview" after major U.S. theater chains pulled out of showing the film following threats from hackers.
Terror threats by hackers spooked the five largest U.S. cinema chains Wednesday into cancelling planned showings of The Interview, Sony's comedy about a plot to kill North Korean leader Kim Jong Un.
Regal Entertainment, AMC Entertainment, Carmike Cinemas, Cinemark and Cinplex Entertainment all said they would not show the film for now, according to The Hollywood ReporteIn a statement, Regal Cinemas said it would "delay" the film's opening in its theatres, due to Sony's "wavering support" for the film "as well as the ambiguous nature of any real or perceived security threats."
Smaller chains have followed suit as well.
Landmark's Sunshine Cinema cancelled the film's New York premiere, set for December 18, late Tuesday, and Arclight Cinemas and Bow Tie Cinemas have dropped its general release.
The cancellations are a major blow to Sony's plans for the 44-million-dollar movie.
Regal, AMC, Cinemark and Carmike alone make up 50 per cent of U.S. box office receipts, the National Association of Theatre Owners told dpa.
Sony has cancelled its planned TV advertising campaign for the film, and was said to be weighing a premium-video-on-demand release instead, according to media reports. Stars James Franco and Seth Rogen have cancelled all media appearances related to the film.
Los Angeles police chief Charlie Beck told KPCC radio, "it does play into the desires of the people that did this and I find that unfortunate."
The threats, delivered a day earlier via ominous email and online messaging site postings that referenced the September 11 terrorist attacks, warned theatres of retribution for showing the film and told audiences to stay away.
The messages were sent by a group calling themselves the Guardians of Peace and purporting to be the hackers responsible for last month's massive breach of Sony Pictures' computer systems.
Hackers who raided Sony's internal systems have wreaked havoc on the company with the systematic release of reams of stolen data since the cyber attack was made public November 24.
An FBI investigation into the hacking is underway. North Korea is a prime suspect, but experts say hackers may have had inside help.
North Korea has denied involvement, but praised the hackers as it has condemned the film.
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