There is enough information to conclude that the North Korean government is responsible for the Sony cyberattack, the FBI said Friday, based on an investigation conducted in collaboration with other government agencies and departments.
"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," the agency said in a statement. "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 U.S. is considering options for a 'proportional' response to the cyberattack. One option is to place North Korea back on the terror list as a state sponsor of terror, Dow Jones reported Friday.
The U.S. is also consulting several countries on the cyberattack, including Japan, South Korea, China and Russia, according to a U.S. official, who added that the U.S. is "working through diplomatic channels to register our concerns and ask for assistance."
Due to sensitive sources and methods to obtain the information, the FBI said it is limited in what it can share. The bureau did say that the conclusion is based on technical analysis of data deletion malware, which revealed that there were links to other malware that North Koreans previously developed. The agency also noticed significant overlap between the infrastructure used in the Sony attack and other malicious digital activity from North Korea.
Shares of Sony were down nearly 3 percent.