U.S. announces new sanctions against North Korea after Sony hacking

The Obama administration on Friday imposed a wave of sanctions against members of the North Korean government, amounting to the U.S. government's first official response to the cyber-attack against Sony Pictures Entertainment.

Despite lingering questions from private security analysts over whether North Korea was responsible for the hack -- as the FBI has alleged -- the White House described the new sanctions as retaliation against Pyongyang.

"We take seriously North Korea's attack that aimed to create destructive financial effects on a U.S. company and to threaten artists and other individuals with the goal of restricting their right to free expression," White House Press Secretary Josh Earnest said in a statement.

"As the president has said, our response to North Korea's attack against Sony Pictures Entertainment will be proportional, and will take place at a time and in a manner of our choosing. Today's actions are the first aspect of our response."

The president signed an executive order authorizing sanctions against agencies and officials associated with the North Korean government and Workers' Party of Korea.

The Treasury Department, in turn, has designated three government-tied entities and 10 North Korean officials under those sanctions. The sanctions would deny them access to the U.S. financial system and bar them from entering the U.S.

In recent days, however, cybersecurity experts in the private sector have raised questions about the allegations North Korea was behind the Sony attack -- which severely disrupted Sony's systems and leaked private communications, embarrassing the company.

One firm, Norse, earlier this week briefed the FBI on evidence it claims could support the theory that the hack was an inside job, involving former Sony staff.