In an automated email reply sent to Variety, the hackers wrote that it will "release the leak gradually every week," adding that the next release may come on "Sunday".
The group also repeated its claim that it had obtained a total of 1.5 terabyte of data when it broke into HBO's computer networks.
The news first broke out on Tuesday when the hackers released a handful of unaired episodes of HBO shows, as well as other internal data, online.