James Franco and Seth Rogen in "The Interview." Ed Araquel/Sony Pictures Entertainment Computer hackers thought to have links to North Korea have published details of Seth Rogen's salary online.

The cyberattack, which is believed to be revenge for the actor's decision to write and star in a film comedy about Kim Jong-un, also revealed the salary of Rogen's costar James Franco.

The documents, as reported by Bloomberg, show Rogen was paid $8.4 million and Franco $6.5 million for their roles in "The Interview," a feature film by Sony Pictures that tells the story of two journalists who land an interview with the North Korean leader and are then recruited by the CIA to take part in a plot to poison him.

North Korea reacted furiously in June when Sony announced its plans for the film, denouncing it as the work of "gangster moviemakers." State media went on to describe the storyline as "a wanton act of terror" that warranted "merciless countermeasures" unless it was canceled.

Stern letters from Pyongyang to Hollywood, the UN, and even the White House failed to have any impact, and it is believed that North Korea has taken matters into its own hands to interfere with the release of the film, which is due to be released in North America on Dec. 25 and in the UK in February.

In an interview with Rolling Stone magazine, due to be published Friday, Rogen reveals that Sony executives became particularly concerned about the impact of the film after North Korea staged a round of missile tests.

"Any time a movie causes a country to threaten nuclear retaliation, the higher-ups wanna get in a room with you," Rogen said, according to the magazine’s website.

As well as publishing the salary details of Rogen and Franco, the hackers also revealed other expenses linked to the film, including $241 spent on "a table of weed, coke, pills, and panties," which is thought to be a prop.

They also published the credit-card number of Michael Lynton, the head of Sony Pictures, and scripts for forthcoming TV programs and placed five Sony films online for free on file-sharing websites. These included the Brad Pitt World War II film "Fury" and "Annie," which stars Jamie Foxx and Cameron Diaz and is due to be released in the US later this month.

California-based Sony has called in the FBI to investigate the attack on its computer systems, along with forensic experts from the cybersecurity firm FireEye Inc.

They have reportedly identified malicious code that is almost exactly the same as the code used in March 2013 to attack numerous South Korean banks and media companies. That cyberattack was widely blamed on North Korea.

A string of cyberattacks on other US businesses, including the DIY retailer Home Depot and Las Vegas Sands Corp., the world's biggest casino operator, have also been linked to North Korea.

Rogan remains defiant about the film, saying in a Twitter post on Sunday: "I personally don't care if it's disrespectful of Kim, because he's evil. But that's not the intent. North Korea has produced tons of propaganda films that portray America's destruction."