HBO CEO says email system 'as a whole' may not be compromised

— -- HBO CEO Richard Plepler told his employees in a memo Wednesday that the hack a few days ago may not be as bad as reported.

In the note, which was obtained by ABC News, Plepler assured employees that teams are working "round the clock" to rectify the situation, and said that fears of a compromised email system may be unfounded.

"Many people have expressed particular concern about our e-mail system. At this time, we do not believe that our e-mail system as a whole has been compromised, but the forensic review is ongoing," he wrote. "We are also in the process of engaging an outside firm to work with our employees to provide credit monitoring and we will be following up with those details."

On Wednesday, Variety reported that the cable network hired a security company to scrub results for hacked files from search engines, and someone from that company told Google that hackers stole "thousands of Home Box Office internal company documents." Those documents, according to Variety, include personal information of a senior HBO executive and data pertaining to HBO employees.

A representative for HBO did not immediately return ABC News' request for comment, though Plepler cautioned staffers to not believe the "enormous amount of speculation in the media."

"Things you read may very well not be true," he wrote.

Two days ago, news broke that hackers allegedly stole 1.5 terabytes of data from HBO, including a script for "Game of Thrones" and upcoming episodes of "Ballers," "Room 104," and "Insecure.”

"HBO recently experienced a cyber incident, which resulted in the compromise of proprietary information," read an earlier statement from HBO. "We immediately began investigating the incident and are working with law enforcement and outside cyber-security firms. Data protection is a top priority at HBO, and we take seriously our responsibility to protect the data we hold."