Time Warner Inc.’s (TWX) HBO is the latest entertainment company grappling with a major data breach as hackers claim that a script for a coming episode of the hit drama show “Game of Thrones” was put online. Entertainment Weekly broke the news of the attack Monday, indicating that the criminals also claim to have put full episodes of comedies “Ballers” and “Room 104” on the Internet. (See also: HBO Plans to Milk Game of Thrones With Four Spinoffs.)

HBO Chief Executive Officer (CEO) Richard Plepler confirmed in a memo to staff that “proprietary information,” including some of its shows, has recently been stolen. The media company is now working with law enforcement and cybersecurity providers in efforts to fix the breach. Spokesman Jeff Cusson did not comment on which specific TV episodes, movies or other videos that the hackers got a hold of.

Recalling the Sony Hack

The headline Sony data breach in 2014, which leaked both employee information and films, demonstrated just how large of an impact cyberattacks can have on Hollywood’s leading players. “The problem before us is unfortunately all too familiar in the world we now find ourselves a part of,” said Plepler.

Earlier this year, hackers released 10 episodes of Netflix Inc.’s (NFLX) popular show “Orange is the New Black” before their release by the on-demand video streaming company.  Soon after, Walt Disney Co. (DIS) CEO Robert Iger told employees in an internal meeting that hackers threatened to post an unreleased film online unless the company agreed to pay a ransom in Bitcoin. Disney took no action and the movie was not released, suggesting that, luckily for entertainment conglomerate, it was all a hoax.   

As cybercriminals develop sophisticated extortion methods and ransomware infections, an estimated 51% of U.S. companies have been hit with a ransomware attack, according to research group Ponemon Institute. (See also: HBO to Remove Shows From Amazon Streaming by End of 2018.)