Doubts on N. Korea claim? FBI briefed on theory Sony hack was inside job

A security firm has brought new evidence to the FBI that it claims points to a laid-off employee and others as the hackers behind the massive cyber-breach at Sony, even as the bureau publicly stands by its explanation that North Korea executed the attack.

Kurt Stammberger, senior vice president for market development at cyber intelligence firm Norse, told FoxNews.com that his company was turning over "raw data" to the FBI on Tuesday. He said the company also briefed the FBI for "two or three hours" on Monday during a meeting in St. Louis.

"They were very open" to the new information, Stammberger said.

Among other details, he said Norse has data about the malware samples that point to "super, super detailed insider information" that only a Sony insider would have.