HBO, which had previously acknowledged the theft of "proprietary information", said it's continuing to investigate and is working with police and cybersecurity experts.
The latest leak includes another half-gigabyte of the total 1.5TB of digital material that hackers stole from HBO. Episodes of the shows "Ballers" and "Room 104" have already appeared online, according to reports.
The demands came in the form of a five-minute video addressed to the network's CEO, Richard Plepler, from a "Mr. Smith", as reported by Business Insider's Alexandra Ma. HBO considered data protection as one of its highest priorities, so it strictly imparted its responsibility towards safeguarding its databases.
The hackers claim they want "our six-month salary in bitcoin" which they say is roughly $6 million (£4.6 million).
The hackers, who illegally broke into HBO's computer networks, claim to have taken 1.5 terabytes of data, including the fourth episode of season seven, which aired in the US on Sunday, and was released illegally on Friday - days after a script from the newest instalment of the fantasy series was published on the Internet. The amount the hackers are demanding would be about $6 million, according to The New York Times.
This is the second HBO-related data dump from the purported hackers.
HBO repeated its earlier assertion that it doesn't believe its entire email system has been compromised by hackers.
The video text was written in often flawed but fluent English peppered with misspellings and pop-culture references.
But the leaks are nowhere near the scale of Sony's meltdown in 2014. In that attack, hackers unearthed thousands of embarrassing emails and released personal information, including salaries and social security numbers, of almost 50,000 current and former Sony employees. The news of hack first broke out on last Tuesday when the hackers reportedly released a handful of unaired episodes of HBO shows, as well as other internal data, online.
Hackers who claim to have accessed HBO seem to be upping the ante.