FBI offers 'proof' North Korea behind cybterattack

FBI Director James Comey revealed new details illustrating why the agency was confident in its assertion that North Korea was behind the cyberattack on Sony Pictures Entertainment. Speaking at the International Conference on Cyber Security in New York on Wednesday, Comey said the hackers "got sloppy," allowing investigators to trace their messages to IP addresses used only in the isolated Asian nation.

Comey explained that although the hackers, who called themselves Guardians of Peace, normally used a proxy server to hide their location, but the few times they forgot to enable the proxy were enough for investigators to determine their true origin.

"It was a mistake by them. They would shut if off very quickly once they realized the mistake, but not before we saw them and knew where it was coming from," Comey said.

The previously secret information was declassified in answer to skepticism from the media at the agency's insistence it had proof North Korea was the source of the attack.

Satire creates international conflict

The hack against Sony included the release of private e-mails and corporate documents, including salaries and social security numbers of employees, as well as threatening messages. The hackers promised 9/11-like violence against theaters who showed "The Interview," a satirical comedy depicting a plan to assassinate North Korean leader Kim Jong Un.

Sony originally cancelled the premiere and pulled the film from cinemas following the threat, only to reverse its decision and release the moviein independent theaters and online.

North Korea continues to deny being behind the attack which prompted the US government to intensify sanctions against the hermit kingdom, including barring important North Korean businesses, agencies, and individuals from using the US financial system and doing business with US firms.

es/bw (AP, dpa)