The hacker or hackers claimed to have stolen an estimated 1.5 terabytes of data, according to Entertainment Weekly, which first reported the breach on Monday. The hacker said more material would be “coming soon.”

The attack is not expected to have any impact on Time Warner’s deal with AT&T, according to two people familiar with the matter, who requested anonymity to discuss private company matters. Only a large material change in Time Warner’s business would prevent the deal from going through, one of the people said.

Unlike Yahoo, which disclosed last year that hackers had stolen the credentials of hundreds of millions of users in two breaches that went undetected for years, HBO does not appear to have sensitive personal information on a similar scale. Because the network typically sells its service through cable or satellite operators, it has not traditionally collected credit card information and other details about its customers. That has changed recently, however, as HBO introduced a stand-alone streaming service in 2015.

Much remains unclear about how much information was obtained in the cyberattack, which can be difficult to determine, said one of the people familiar with the breach. The person said the stolen content included a few show episodes, scripts and internal documents, like human resources records.

There is no evidence yet that any episodes of “Game of Thrones” have been stolen, which would be a significant blow to the network. “Game of Thrones,” currently in its penultimate season, is the most popular show in HBO’s history and has long been a target of digital piracy. There are four highly anticipated episodes left in the season.