Sony Hackers 'Got Sloppy' And Left Fingerprints

The hackers behind the cyberattack on Sony (Swiss: SONC.SW - news) "got sloppy" and left a trail which leads back to North Korea, the FBI has revealed.

Amid persistent scepticism about whether North Korea's government was responsible for the hacking, FBI director James Comey spoke out at a cyber-security conference.

He said the hackers mistakenly sent messages that were traced to IP addresses used only by North Korea.

Those responsible had tried to use proxy computer servers to disguise their identities and throw investigators off their trail by hiding their true locations.

Mr Comey added: "It was a mistake by them. It made it very clear who was doing this.

"I have very high confidence about this attribution to North Korea, as does the entire intelligence community."

It was first reported on 20 December that the FBI had discovered that computer Internet addresses known to be operated by North Korea were communicating directly with other computers used to control the hacking tools and collect stolen Sony files.

It was apparently in response to the impending release of The Interview, a comedy film which pokes fun at the secretive regime.

North Korea has always denied being involved in the hacking.

Mr Comey said the evidence should undermine continuing scepticism by some cyber experts that individual hackers or a disgruntled insider may have been the culprits.

"They don't have the facts that I have, don't see what I see," he said.

Earlier this week, Sony chief executive Kazuo Hirai broke his silence about the attack, saying he was proud of his employees for standing against "the extortionist efforts of criminals".