A hack of Home Box Office Inc. first reported earlier this week is now believed to be significantly larger than first thought and could include potentially damaging internal company correspondence, according to reports published Wednesday.

The hack of HBO was first revealed July 31 when hackers claimed to have stolen data from the company including upcoming episodes of television programs and a script for a future episode of the hit show “Game of Thrones.” HBO confirmed the hack, saying in a statement that it had “experienced a cyber incident which resulted in the compromise of proprietary information” and that it was investigating the incident.

Two days later, the “incident” appears to be far bigger than first thought, with some claiming that it may be larger than the infamous hack of Sony Pictures Entertainment in 2014. The hack, which is believed to have involved a staggering 1.5 terabytes of data, seven times the size of the Sony hack, targeted specific content and data housed in different locations.

No ransom demand has been forthcoming. The Hollywood Reporter quoted sources who said this leaves the motive for the hack in question and raises the “specter that video footage, internal documents or even email correspondence could be leaked.”

In addition to the release of episodes of various television shows, it is known that the hacked data includes personal information for Viviane Eisenberg, HBO’s executive vice president of legal affairs, covering usernames and passwords for a bizarrely long list of her accounts:

“Facebook, LinkedIn, Gmail, DropBox, Apple, HBO account, Blackberry, Continental Airlines, credit card numbers and related details, Easy Pay MetroCard, Columbia University account, Amex card number, Cardozo School of Law account, American airlines advantage number, SkyMiles, Richard Mellen Easy Pay MetroCard, The Economist account, Evernote, HSBC account, New York City Bar, New York State Bar Association, New Yorker Magazine, PayPal, Time Warner Cable, United HealthCare, UPS and Verizon.”

According to Hackread, the list includes an additional 20 more plain text logins and password details allegedly belonging to Eisenberg’s personal, banking and media related information.

Internal documents

Leaked data described as “internal documents” have also been leaked by the hackers. Variety claims that a security company hired by HBO to scrub search results for the hacked files from search engines has told Google Inc. that the hackers stole “thousands of HBO internal company documents.” The same report notes that the Digital Millennium Copyright Act, or DMCA, notice filed by IP Echelon on HBO’s behalf covered “copyrighted items including documents, images, videos and sound.”

The site targeted in one DMCA notice, called winter-link.com, is down at the time of writing. However, a search through the Internet Archive finds a copy of the site from Aug. 1 that includes downloads for a number of HBO shows and Eisenberg’s info but does not include any further internal company documents or emails.

With the Federal Bureau of Investigation said to be investigating the hack, and Mandiant, the cybersecurity consulting division of FireEye Inc. hired by HBO to undertake forensic analysis, what we know so far may be the tip of the iceberg.

Image: Winter-leak