Did North Korea Really Attack Sony?

I am deeply skeptical of the FBI’s announcement on Friday that North Korea was behind last month’s Sony hack. The agency’s evidence is tenuous, and I have a hard time believing it. But I also have trouble believing that the US government would make the accusation this formally if officials didn’t believe it.

Clues in the hackers’ attack code seem to point in all directions at once. The FBI points to reused code from previous attacks associated with North Korea, as well as similarities in the networks used to launch the attacks. Korean language in the code also suggests a Korean origin, though not necessarily a North Korean one, since North Koreans use a unique dialect. However you read it, this sort of evidence is circumstantial at best. It’s easy to fake, and it’s even easier to interpret it incorrectly. In general, it’s a situation that rapidly devolves into storytelling, where analysts pick bits and pieces of the “evidence” to suit the narrative they already have worked out in their heads.

In reality, there are several possibilities to consider:

This is an official North Korean military operation. We know that North Korea has extensive cyberattack capabilities.

This is the work of independent North Korean nationals. Many politically motivated hacking incidents in the past have not been government-controlled. There’s nothing special or sophisticated about this hack that would indicate a government operation. In fact, reusing old attack code is a sign of a more conventional hacker being behind this.

This is the work of hackers who had no idea that there was a North Korean connection to Sony until they read about it in the media. Sony, after all, is a company that hackers have loved to hate for a decade. The most compelling evidence for this scenario is that the explicit North Korean connection — threats about the movie The Interview — were only made by the hackers after the media picked up on the possible links between the film release and the cyberattack. There is still the very real possibility that the hackers are in it just for the lulz, and that this international geopolitical angle simply makes the whole thing funnier.

— were only made by the hackers the media picked up on the possible links between the film release and the cyberattack. There is still the very real possibility that the hackers are in it just for the lulz, and that this international geopolitical angle simply makes the whole thing funnier. It could have been an insider — Sony’s Snowden — who orchestrated the breach. I doubt this theory, because an insider wouldn’t need all the hacker tools that were used. I’ve also seen speculation that the culprit was a disgruntled ex-employee. It’s possible, but that employee or ex-employee would have also had to possess the requisite hacking skills, which seems unlikely.

The initial attack was not a North Korean government operation, but was co-opted by the government. There’s no reason to believe that the hackers who initially stole the information from Sony are the same ones who threatened the company over the movie. Maybe there are several attackers working independently. Maybe the independent North Korean hackers turned their work over to the government when the job got too big to handle. Maybe the North Koreans hacked the hackers.

I’m sure there are other possibilities that I haven’t thought of, and it wouldn’t surprise me if what’s really going on isn’t even on my list. North Korea’s offer to help with the investigation doesn’t clear matters up at all.

Tellingly, the FBI’s press release says that the bureau’s conclusion is only based “in part” on these clues. This leaves open the possibility that the government has classified evidence that North Korea is behind the attack. The NSA has been trying to eavesdrop on North Korea’s government communications since the Korean War, and it’s reasonable to assume that its analysts are in pretty deep. The agency might have intelligence on the planning process for the hack. It might, say, have phone calls discussing the project, weekly PowerPoint status reports, or even Kim Jong Un’s sign-off on the plan.

On the other hand, maybe not. I could have written the same thing about Iraq’s weapons of mass destruction program in the run-up to the 2003 invasion of that country, and we all know how wrong the government was about that.

Allan Friedman, a research scientist at George Washington University’s Cyber Security Policy Research Institute, told me that, from a diplomatic perspective, it’s a smart strategy for the US to be overconfident in assigning blame for the cyberattacks. Beyond the politics of this particular attack, the long-term US interest is to discourage other nations from engaging in similar behavior. If the North Korean government continues denying its involvement, no matter what the truth is, and the real attackers have gone underground, then the US decision to claim omnipotent powers of attribution serves as a warning to others that they will get caught if they try something like this.

Sony also has a vested interest in the hack being the work of North Korea. The company is going to be on the receiving end of a dozen or more lawsuits — from employees, ex-employees, investors, partners, and so on. Harvard Law professor Jonathan Zittrain opined that having this attack characterized as an act of terrorism or war, or the work of a foreign power, might earn the company some degree of immunity from these lawsuits.

I worry that this case echoes the “we have evidence — trust us” story that the Bush administration told in the run-up to the Iraq invasion. Identifying the origin of a cyberattack is very difficult, and when it is possible, the process of attributing responsibility can take months. While I am confident that there will be no US military retribution because of this, I think the best response is to calm down and be skeptical of tidy explanations until more is known.

This essay originally appeared on The Atlantic.

Lots more doubters. And Ed Felten has also written about the Sony breach.

EDITED TO ADD (12/24): Nicholas Weaver analyzes how the NSA could determine if North Korea was behind the Sony hack. And Jack Goldsmith discusses the US government’s legal and policy confusion surrounding the attack.

EDITED TO ADD: Slashdot thread. Hacker News thread.

EDITED TO ADD (1/14): Interesting article by DEFCON’s director of security operations.

Posted on December 24, 2014 at 6:27 AM • 120 Comments