U.S. officials now believe North Korea is behind the attack that took down Sony Pictures Entertainment's computer network and posted contents on the Internet, but the government hasn't decided whether to formally accuse the country of carrying out the hack, according to The New York Times.
The Obama administration is split on how to respond, with some in the White House concerned there might be no effective punishment to deliver and that it might have some embarrassing explaining to do about how it came to that conclusion – especially if hacking North Korean networks by the U.S. were involved, the story says.
The attack on Sony, prompted by its unreleased comedy film "The Interview" about a CIA attempt on North Korean leader Kim Jong-un's life, is one of the most destructive cyber attacks ever, and likely has the backing of a foreign government, experts say.
But retaliating against North Korea would be tricky because it could have repercussions for U.S. allies such as Japan, which is in negotiations with North Korea for the return of kidnapped citizens, the Times story says.
The situation has escalated, with those taking responsibility for the hack threatening to attack movie theaters where the film is shown. Although vague, the threat makes reference to the World Trade Center attacks: "Remember the 11th of September 2001. We recommend you keep yourself distant from the places at that time."
A U.S. official characterized that as transforming the attack against a corporation "into a threat to the safety of Americans," according to the Times story.
At the same time the attack has had serious implications for Sony. General release of "The Interview" has been cancelled, other Sony movies have been posted on the Internet for anyone to download, works in progress have been revealed and private emails never meant for public consumption have been released. Sony is now threatening legal action against anyone reposting the stolen information, and former Sony employees are suing the company for failure to adequately protect their personal data.
It's still unclear how the attack unfolded, but suspicions include the possibility of insiders collaborating with attackers from overseas.