HBO offered a reward of $250,000 in response to a data breach at the television group that produces "Game of Thrones," according to a report from a leaked memo.

The report by Variety on Thursday said HBO offered the payment as a "bug bounty," which is offered by companies to discover vulnerabilities in their computer networks.

The offer apparently failed to satisfy the attackers who have demanded a ransom of millions of dollars and are threatening to release more files from what is claimed to be a massive data breach.

HBO, a unit of the media group Time Warner, did not respond to a query about the Variety report.

Read also: HBO hackers demand millions in ransom note

Earlier this week, a video circulating online authored by someone identified only as "Mr. Smith" said the hackers had videos, scripts, personnel files and other sensitive data from the breach.

The hackers demanded "six month salary," which, according to the video, would be more than $6 million.

Last week the hacker group leaked one script of "Games of Thrones" and content from other HBO productions.

HBO has said it was working with forensic experts and law enforcement in response to the attack.