North Korea denied involvement Sunday in a cyber attack on Sony Pictures, but praised it as a "righteous deed" potentially carried out by its supporters to protest against a film featuring its leader Kim Jong-Un.

"The hacking into the Sony Pictures might be a righteous deed of the supporters and sympathizers with the (North) in response to its appeal," the North's top military body, the National Defense Commission, told the state-run KCNA news agency.

"The Interview" -- a comedy film by Sony involving a fictional CIA plot to assassinate Kim -- has infuriated Pyongyang, which earlier warned of "merciless retaliation".

The latest hacking attack on the US movie studio is known to have included the leaking of sensitive personal information on some 47,000 individuals, including celebrities.

The attack also made unreleased Sony films available on illegal file-sharing websites, with media reports indicating the pattern matches past attacks carried out by the isolated state.

The NDC rejected the media reports as "false rumour" but went on to slam Sony for producing the film "abetting a terrorist act while hurting the dignity of the supreme leadership of the (North)."