Sony Pictures is reportedly investigating whether the North Korean regime was behind a massive hack attack on the studio's network last week. 

The technology news website Re/code, citing sources familiar with the attack, said that the studio and its outside security consultants is exploring the possibility that hackers based in China had targeted studio computers in retaliation for the upcoming release of the film "The Interview."

North Korea has repeatedly expressed indignation about the film, a comedy that stars Seth Rogen and James Franco as journalists who are enlisted by the CIA to assassinate dictator Kim Jong-un. Re/code reported that sources had not confirmed that the hack and the film's release were linked, but a connection has not been ruled out, either. 

On Friday, Uriminzokkiri, a website run by the North Korean government, called "The Interview" an "evil act of provocation" that deserved "stern punishment." The Daily Telegraph, citing the Police Policy Institute, a South Korean think tank, reported that North Korea had organized a team of approximately 3,000 hackers to promote the Kim regime. 

The hackers, who have adopted the code name "Guardians of Peace," took over Sony Pictures' internal corporate network Nov. 24. They posted a message promising to release sensitive corporate data if certain demands were not met by 6 p.m. EST. It was not clear whether the hackers followed through with their threat.

The attack reportedly forced staffers to use pen and paper to complete work assignments. Sony has declined to officially comment beyond a Tuesday statement acknowledging a "system disruption" that the company was "working diligently to resolve." However, The New York Times reported that Sony's information technology experts told an in-house conference call they were "making inroads" against the attack and expected to be back online by Monday. 

Meanwhile, Variety reported that screener copies of at least five Sony movies were being downloaded freely online following the hack. Four of the movies, including a remake of the musical "Annie", have yet to be released, while the fifth, World War II epic "Fury", is still in theaters.