Sony Corp.'s film and TV studio may have had several films stolen, including two that have yet to be released, in a Tuesday cyberattack that may be linked to North Korea, a person with knowledge of the matter said.

The recent picture "Fury," a Brad Pitt war movie, and the yet-to-be-released "Annie" and "Still Alice" have appeared on file-sharing sites, said the source, who sought anonymity because of the sensitive nature of the matter. The website TorrentFreak, a news site on file-sharing, said "Fury" was the No. 2 most-downloaded film at one site.

The hacking incident at Sony Pictures Entertainment, which continues to cripple its computer systems, began when a picture of a skull appeared on company computer screens. The image was accompanied by a message that read Sony had been hacked by #GOP, believed to stand for "Guardians of Peace," and that private data would be released if undisclosed demands weren't met.