The hackers who were responsible for stealing and publishing unreleased episodes of HBO programming and other internal company documents are threatening to publish more stolen content this Sunday, August 6.

In an email cited by Variety, the group behind the hack—which has identified itself as little.finger66 — said it would “release the leak gradually every week,” with the next planned release set to happen Sunday at “12 GMT.” Whether that is a.m. or p.m. was not specified.

Read: HBO Hack: FBI Reportedly Investigating Incident, Full Episodes Stolen

It is not clear what may be included in upcoming releases from the group, which stolen 1.5 terabytes worth of data from the network. A previous release included full episodes of “Ballers,” “Room 104,” “Barry” and “Insecure.” Partial scripts from “Game of Thrones” were also stolen.

HBO did not immediately respond to the latest threat from the hackers.

On Wednesday, fears began to spread that internal communications including emails may have been included in the theft, as the hack appeared to encompass multiple computer systems operated by the company.

HBO president and CEO Richard Plepler informed employees the hackers likely didn’t break into its email system. “At this time, we do not believe that our email system as a whole has been compromised, but the forensic review is ongoing,” he said, according to Variety.

Variety also reported a security contractor hired by HBO to remove search results for the leaked data from search engines like Google revealed that the hackers did manage to steal “thousands of internal documents.”

Read: 'Game of Thrones' Season 7, 'Ballers' Spoilers Leak In HBO Hack

Thus far, the majority of the information leaked online by the hackers have been intellectual property. Photos, videos, scripts and other valuable files were all published to a website set up by the hacking group. The site, WinterLeak, has been offline and inaccessible for two days.

While the HBO hack is sizable and has resulted in a significant amount of information with value to the company being leaked online, it does not appear to have the same motivations as the 2014 hack of Sony Pictures.

That attack, in which the hackers claimed to have stolen 100TB of data, was an international cyber incident that prompted a response from the President of the United States and other intelligence agencies. The North Korean government was believed to be behind that attack, while there has not been a state actor linked to the HBO attack.

HBO is just the latest Hollywood entity to be targeted by hackers, but the occurrence appears more targeted and malicious than other recent incidents. Unlike the theft of “Orange Is The New Black” and the supposed theft-turned-hoax of “Pirates Of The Caribbean: Dead Men Tell No Tales,” there was no ransom attempt made against HBO.

Prior attacks also were the result of larger sweeps that just happened to produce the stolen content. In the case of HBO, the attack seemed to be targeted, hitting multiple points of entry in the company’s computer network. Ferruh Mavituna, CEO of web security firm Netsparker, told International Business Times the hack may have exploited weaknesses in web applications used by the company.