The notorious hacking organization OurMine appears to have taken over HBO's official Twitter accounts, including "Game of Thrones" and "Silicon Valley."

HBO’s security continues to be attacked online — this time, by a so-called security group

Late Wednesday night, the notorious hacking group OurMine sent messages over HBO’s official Twitter and Facebook accounts that read:

“Hi, OurMine are here, we are just testing your security ,HBO team please contact us to upgrade the security – ourmine .org -> Contact”

OurMine is well-known for infiltrating big-name accounts. In the past, the organization has taken over the social media accounts of Netflix, Marvel, and Google. They’ve hacked into YouTube, as well as other celebrity accounts.

During Wednesday night’s breach, they accessed accounts for “Game of Thrones,” “The Leftovers,” “Silicon Valley,” “Veep,” “Last Week Tonight,” “Girls,” “Ballers,” “The Knick,” “The Comeback,” “Real Sports,” “Looking,” “Vinyl,” “Outcast,” “Any Given Wednesday,” Cinemax, HBO Docs, HBOboxing, HBO Now, HBO Now Help, HBOGo Help, and HBO Careers.

Typically, the attacks only extend so far as to show what the hackers are capable of, and they do not release protected information.

HBO was able to scrub most messages after they were up for just a few minutes.

https://twitter.com/awallenstein/sta...20854302294017

The hack comes on the heels of separate attacks earlier on Wednesday and many more during the previous weeks. The sixth episode of this “Game of Thrones” season was accidentally leaked online early Wednesday, but that was an in-house error.

“We have learned that the upcoming episode of ‘Game of Thrones’ was accidentally posted for a brief time on the HBO Nordic and HBO Espaņa platforms,” Tom Krogsgaard Nielsen, VP of public relations for HBO Europe, said in a statement. “This is not connected to the recent cyber-incident at HBO in the U.S.”

The episode was only up for a short period of time, but long enough for piracy sites and torrent networks to get their hands on it.

Previous episodes of “Game of Thrones” and other HBO shows were released by other hackers. Four arrests were made in India on Wednesday related to illegally releasing an episode online, but those weren’t related to an earlier hack that reportedly included proprietary information from HBO’s servers.

On Sunday, unaired episodes of “Curb Your Enthusiasm,” “Ballers,” and “Insecure” were released online.