A massive Sony Pictures hack that allowed attackers to steal an estimated 11 terabytes of data has been followed by the online release of a number of upcoming movies. Fury, Annie, and Mr. Turner are among the films thought to have been uploaded by a group that calls itself the Guardians of Peace.

Sony is no stranger to system hacks, but this one is almost certainly its worst yet.

Last Monday, computers owned by Sony Pictures were hijacked and an incredible amount of digital data was stolen from them. In addition to unreleased movies, hackers obtained sensitive corporate information and warned that it would be released into the wild if its demands were not met, TorrentFreak reports.

“We’ve obtained all your internal data including your secrets and top secrets,” read a message left for Sony by the Guardians of Peace. “If you don’t obey us, we’ll release data shown below to the world.” Sony was given a deadline of 11 p.m. GMT on November 24.

It’s still unclear who was behind the hack, but sources for Recode have suggested it could be a Chinese agency working on behalf of North Korea. The hack comes just as Sony is gearing up to release The Interview, a movie starring Seth Rogen and James Franco, which depicts a CIA plot to assassinate North Korean leader Kim Jong-Un.

North Korean propaganda outlets have already promised “merciless retaliation” against the U.S. and other nations if the film is released.

Among the sensitive data that was stolen is thought to be passport and visa information for the cast and crew working on various Sony Pictures movies, as well as email inboxes, documents detailing the company’s internal computer systems, and its accounting information.

The movies already released online, which are DVD-quality copies that still contain Sony watermarks, are Fury, Still Alice, Annie, Mr. Turner, and To Write Love On Her Arms — only one of which, Fury, has officially been released in the U.S. No one can be certain if these leaks have anything to do with the Sony system hack, but it seems more than just coincidence at this point.

Sony Pictures has maintained a fairly silent stance as it has worked to quickly bring its systems back online and restore emails over Thanksgiving, but a spokesperson told Deadline that the theft is a “criminal matter” that Sony is working to address with law enforcement agencies.