The Federal Bureau of Investigation formally blamed North Korea for the cyberattack against Sony Pictures in a statement on Friday, saying "we are deeply concerned about the destructive nature of this attack on a private sector entity, and the ordinary citizens who worked there."
North Korea had denied involvement in the attacks, which were carried out by a group calling itself "Guardians of the Peace," Reuters notes.
The hackers leaked emails, yet-to-be-released Sony films, and personal information about the company's employees on the internet. The group also made threats against movie theaters that planned to show The Interview, a movie starring Seth Rogen and James Franco, in which the actors attempt to assassinate North Korean leader Kim Jong Un. Those threats ultimately prompted Sony to cancel the film's Christmas Day release.