AUDIE CORNISH, HOST:
For three days now, a drama has been unfolding at HBO. They've been hacked. Company information was stolen...
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CORNISH: ...Including programming materials possibly from "Game Of Thrones." Now, this isn't the first time a major entertainment company has been hacked. Sony and Netflix have also had material taken. NPR's Elizabeth Blair reports.
ELIZABETH BLAIR, BYLINE: Past hackers have had dramatic names. The Guardians of Peace claimed responsibility for the Sony hack. The Dark Overlord hacked Netflix and stole episodes of "Orange Is The New Black."
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REGINA SPEKTOR: (Singing) The animals, the animals trapped, trapped, trapped till the cage is full.
BLAIR: The HBO hacker's name is less ominous. LittleFinger66 claims in an email, we hacked HBO, and 1.5 TB of sensitive data and films is in our hands. The message continues, we release the leak gradually every week. One-point-five TB, or terabytes, could hold hundreds of hours of video. There are reports LittleFinger66 has released upcoming episodes of shows including "Ballers" and "Insecure." But it's too soon to know if all of the hacker's claims are true, says Avivah Litan, a security analyst with Gartner.
AVIVAH LITAN: It takes companies like HBO weeks to figure out exactly what happened. You know, some companies can figure it out much more quickly because they're prepared for incidents like this.
BLAIR: Litan has spoken with people who are helping HBO with their investigation. She says the indications are pretty strong that the hackers targeted desktops.
LITAN: The main way bad guys get into corporate networks is through desktops. So you know, one possible path was they got onto desktops. They stole whatever they found easily on these employee desktops. And then they kept going until they found "Game Of Thrones" and other shows that they wanted to steal.
BLAIR: Litan says hackers have gotten very sophisticated and that companies around the world need much more advanced security systems to prevent an attack. When the FBI was investigating the cyberattack against Sony, then-Director James Comey blamed North Korea. Here he is in 2015 speaking at a cyber security conference in New York.
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JAMES COMEY: And we could see that the IP addresses that were being used to post and to send the emails were coming from IPs that were exclusively used by the North Koreans. It was a mistake by them that we haven't told you about before that was a very clear indication of who was doing this.
BLAIR: Avivah Litan says it's too soon to say who's behind the HBO hack.
LITAN: It would be easy to take a leap and say this is North Korea being mischievous and just trying to disrupt American business. And they love to go after our entertainment business because that's one of our most popular exports around the world, and it really hits us where it hurts culturally. And it could be true, but it could just be some cyber criminals trying to make money on HBO.
BLAIR: Meantime, HBO says their forensic review of the hacking incident is ongoing. They also said they believe their email system has not been compromised unlike what happened at Sony. Elizabeth Blair, NPR News. Transcript provided by NPR, Copyright NPR.