The Federal Bureau of Investigation confirmed on Dec. 19 that the United States has concluded that the government of North Korea is the culprit behind the attack that has disrupted Sony Pictures Entertainment's business.
In a statement published on the law enforcement agency's Website, the FBI and private-industry experts concluded that the attack showed similarities to previous North Korean operations in a number of technical ways, including coding similarities, the use of the same encryption algorithms, common data deletion methods, and the use of the same compromised networks observed in previous attacks. The attackers also used the same infrastructure as other attacks attributed to North Korea.
While an unknown group calling itself the "Guardians of Peace" has claimed responsibility for the attack, the United States considers the attack to be a nation-state operation, the FBI stated.
"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," the agency said.
The attack on Sony Pictures is one of the most serious cyber-attacks yet documented. In late November, the company revealed that attackers had stolen tens of terabytes of information from Sony Pictures and then attempted to hide their tracks by deleting data on the company's systems.
On Dec. 17, the company canceled the release of the satirical movie, The Interview, after terrorist threats allegedly made by the "Guardians of Peace" attackers led four major theater chains to refuse to screen the movie.
President Obama called the company's capitulation to the demands "a mistake" on Dec. 19. "They caused a lot of damage and we will respond, we will respond proportionally and we will respond in a place and time we choose," he said during a press briefing. "We cannot have a society in which some dictator someplace can start imposing censorship in the United States."
The attack is also a parable of the dangers of lax security. Administrators at Sony Pictures appear to have left passwords in a folder on one of the company's systems. In addition, the company's security team appears to mostly consist of management, which has led some to accuse the firm of having a "top-heavy" security team.
The FBI praised Sony Pictures for coming forward so quickly and criticized the attackers for targeting a private company.
"We are deeply concerned about the destructive nature of this attack on a private sector entity and the ordinary citizens who worked there," the FBI stated. "Further, North Korea's attack on SPE reaffirms that cyber-threats pose one of the gravest national security dangers to the United States."
While the evidence may point to North Korea, the technical evidence could be faked, Adam Kujawa, head of malware intelligence at endpoint security firm Malwarebytes, stressed in a statement to eWEEK. The actions of the hackers do not necessarily align with nation-state actors, he said.
"What we know about [North Korea] is that they like to brag when they do something, yet they have announced, not only to the world but also to their own information-censored country that they didn't do anything," Kujawa said. "Until we know all the facts, and I seriously doubt we will ever know them all, making quick assumptions and jumping the gun is ill-advised."