Sony Pictures still has no idea who is behind the catastrophic attack that rendered its company-wide computer system useless on Monday, but the company is not taking out the possibility that hackers from North Korea, possibly operating out of China, are behind the attack.

Re/code cites people familiar with the matter who say that Sony is investigating this particular line of thinking because of "The Interview", a soon-to-be-released comedy film about the assassination of North Korean leader Kim Jong-Un. The film, which stars actors Seth Rogers and James Franco, features two journalists who win a one-in-a-million interview with Kim Jong-Un, played by Randall Park. The journalists are then enlisted by the CIA to kill the North Korean leader.

As Kim Myong-chol, director for the Center for North Korea-U.S. Peace told the Daily Telegraph after seeing the film's trailer said, Kim Jong-Un is not happy about being the target of assassination attempts in a movie and warns that those behind "The Interview" will suffer "merciless retaliation".  

"A film about the assassination of a foreign leader mirrors what the U.S. has done in Afghanistan, Iraq, Syria and Ukraine," he said. "And let us not forget who killed Kennedy - Americans. In fact, President Obama should be careful in case the U.S. military wants to kill him as well."

However, The Verge has also been in contact with persons who claim to be responsible for the attack. The representative, nicknamed Lena, says the attack was carried out as a protest for "equality" and suggests that it was successful because the attackers obtained the assistance of people working inside the company.

"Sony doesn't lock their doors, physically, so we worked with other staff with similar interests to get in," Lena writes in an email associated with the attack. "I'm sorry I can't say more, safety for our team is important [sic]."  

On Monday, employees at Sony's Culver City headquarters and New York City office had their computer screens showing a glowering red skull with a message saying "Hacked by #GOP", which a Sony insider says the company believes to stand for Guardians of Peace. The message threatened to release sensitive company information obtained by the hackers if Sony does not satisfy demands made by the hackers, although it is unclear what those demands are or whether Sony are aware of them.

The message also shows a list of links containing the file names of the documents obtained by the hackers, which consist of PDF files containing passwords and password hints, accounting and research spreadsheets, hundreds of Outlook email archives, media files not produced by Sony and passports of actors and actresses that have worked with Sony, including Jonah Hill, Angelina Jolie and Cameron Diaz.

Sony has shut down its computer network for its California and New York offices, and all other offices around the world have zero or limited access. The company, which says it is currently investigating an "IT matter", could likely take up to three weeks to get back online, while workers have resorted to the old-fashioned method of using pen and paper to work. On Tuesday, the company released a short statement about the current developments.

"Sony Pictures Entertainment experienced a system disruption, which we are working diligently to resolve," Sony says.