The FBI has formally accused North Korea of being behind the Sony hack

That’s it, it’s official: the US government has now formally accused North Korea of the crippling Sony Pictures hack, following earlier reports of an impending announcement.

The FBI’s statement says, despite some earlier reservations, that there is finally “enough information to conclude that North Korean government is responsible for these actions.” It notes that while it can’t share all the information it has, there are at least three important clues it used to determine culpability.

• The malware used in the attack links to other tools the FBI had previously known North Korean hackers to develop. Specific lines of codes and compromised networks were cited.
• There were several IP addresses associated with North Korean infrastructure discovered through the data deletion malware used in the attack.
• The tools used here were similar to a North Korean attack in March of 2013 against South Korean banks and media.

This isn’t so different from what security researchers and media outlets had claimed prior to today’s accusation, but again, the FBI isn’t revealing all of its sources. The Bureau notes it is “deeply concerned” about this attack’s effect on the private sector and ordinary citizens, saying the pervasiveness of the Sony hack “sets it apart.”

Working together with domestic and foreign partners, “the FBI will identify, pursue, and impose costs and consequences on individuals, groups, or nation states who use cyber means to threaten the United States or U.S. interests.”

Update: At a news conference today, President Obama finally addressed the Sony hacks at length – directly blaming North Korea himself. Here are some choice quotes from the event:

“We cannot have a society in which some dictator can start imposing censorship in our state.”

“Imagine if producers start self-censoring because they don’t want to offend someone who’s sensibilities probably need to be offended. That’s not who we are. That’s not what America’s about.”

“All of us have to anticipate that there are going to be breaches like this. But we can’t start changing our patterns of behavior than we stop going to a football game because there’s a possibility of a terrorist attack. Let’s not get into that way of doing business.”

On the notion of North Korea working with other countries, Obama said “We have no indication that North Korea was acting in conjunction with another country.” So while North Korea could have kept the involved servers outside of the country itself, there seems to be no clear evidence it was working with any partner nations to perpetuate its attack.

The President says the United States will respond to the attacks “proportionally”, and intends to begin lay down stronger rules and guidelines for how to deal with issues of cybersecurity in the future.

Here’s the full FBI statement:

Today, the FBI would like to provide an update on the status of our investigation into the cyber attack targeting Sony Pictures Entertainment (SPE). In late November, SPE confirmed that it was the victim of a cyber attack that destroyed systems and stole large quantities of personal and commercial data. A group calling itself the “Guardians of Peace” claimed responsibility for the attack and subsequently issued threats against SPE, its employees, and theaters that distribute its movies.

The FBI has determined that the intrusion into SPE’s network consisted of the deployment of destructive malware and the theft of proprietary information as well as employees’ personally identifiable information and confidential communications. The attacks also rendered thousands of SPE’s computers inoperable, forced SPE to take its entire computer network offline, and significantly disrupted the company’s business operations.

After discovering the intrusion into its network, SPE requested the FBI’s assistance. Since then, the FBI has been working closely with the company throughout the investigation. Sony has been a great partner in the investigation, and continues to work closely with the FBI. Sony reported this incident within hours, which is what the FBI hopes all companies will do when facing a cyber attack. Sony’s quick reporting facilitated the investigators’ ability to do their jobs, and ultimately to identify the source of these attacks.

As a result of our investigation, and in close collaboration with other U.S. government departments and agencies, the FBI now has enough information to conclude that the North Korean government is responsible for these actions. While the need to protect sensitive sources and methods precludes us from sharing all of this information, our conclusion is based, in part, on the following:

• Technical analysis of the data deletion malware used in this attack revealed links to other malware that the FBI knows North Korean actors previously developed. For example, there were similarities in specific lines of code, encryption algorithms, data deletion methods, and compromised networks.
• The FBI also observed significant overlap between the infrastructure used in this attack and other malicious cyber activity the U.S. government has previously linked directly to North Korea. For example, the FBI discovered that several Internet protocol (IP) addresses associated with known North Korean infrastructure communicated with IP addresses that were hardcoded into the data deletion malware used in this attack.
• Separately, the tools used in the SPE attack have similarities to a cyber attack in March of last year against South Korean banks and media outlets, which was carried out by North Korea.

We are deeply concerned about the destructive nature of this attack on a private sector entity and the ordinary citizens who worked there. Further, North Korea’s attack on SPE reaffirms that cyber threats pose one of the gravest national security dangers to the United States. Though the FBI has seen a wide variety and increasing number of cyber intrusions, the destructive nature of this attack, coupled with its coercive nature, sets it apart. North Korea’s actions were intended to inflict significant harm on a U.S. business and suppress the right of American citizens to express themselves. Such acts of intimidation fall outside the bounds of acceptable state behavior. The FBI takes seriously any attempt—whether through cyber-enabled means, threats of violence, or otherwise—to undermine the economic and social prosperity of our citizens.

The FBI stands ready to assist any U.S. company that is the victim of a destructive cyber attack or breach of confidential business information. Further, the FBI will continue to work closely with multiple departments and agencies as well as with domestic, foreign, and private sector partners who have played a critical role in our ability to trace this and other cyber threats to their source. Working together, the FBI will identify, pursue, and impose costs and consequences on individuals, groups, or nation states who use cyber means to threaten the United States or U.S. interests.

➤ Update on Sony Investigation [FBI]