Nikolaj Coster-Waldau as Jaime Lanniste. Picture: Macall B. Polay/HBO via AP

New York – The purported HBO hackers are demanding that HBO pay a ransom of several million dollars to prevent further releases of confidential files and program-related material.

In a video directed to HBO CEO Richard Plepler, the hackers — who use the pseudonym "Mr. Smith" — used white text on a black background to threaten further disclosures if HBO doesn't pay up. To stop the leaks, the purported hackers demanded "our 6 month salary in bitcoin," which they implied is at least $6 million (over R79 million).

This is the second HBO-related data dump from the hackers. So far the HBO leaks have been limited, falling well short of the chaos inflicted on Sony in 2014. In that attack, hackers unearthed thousands of embarrassing emails and released personal information, including salaries and social security numbers, of nearly 50 000 current and former Sony employees.

Hackers using the name "Mr. Smith" posted a fresh cache of stolen HBO files, including some apparently related to the show "Game of Thrones," online Monday, part of what the hackers have claimed is a much larger trove of stolen HBO material.

The dump includes scripts from five "Game of Thrones" episodes, including one upcoming episode, and a month's worth of email from the account of an HBO programming executive.

HBO, which previously acknowledged the theft of "proprietary information," says it's continuing to investigate and is working with police and cybersecurity experts.