FBI Director James Comey has released new details on the Sony Corp. hack, noting that the hackers were “sloppy” in trying to cover their tracks.

Comey in particular noted that the hackers had failed to use proxy servers to hide their identity, and that IP addresses used exclusively by the North Korean government were used in the attack.

“The Guardians of Peace would send emails threatening Sony employees and post online various statements explaining their work. In nearly every case they would use proxy servers in sending those emails and posting those statements,” Comey said.

“But several times they got sloppy. Several times, either because they forgot or they had a technical problem, they connected directly and we could see it.”

“We could see that the IP addresses they used … were IPs that were exclusively used by the North Koreans. It was a mistake by them. It was a very clear indication of who was doing this. They would shut it off very quickly once they realized the mistake, but not before we saw them and knew where it was coming from,” he added.

The finger was first pointed at North Korea over Sony hacking by the Government December 19th although at the time some were skeptical that the hermit kingdom had the ability to undertake an attack of this sort.

Comey further noted that investigators still do not know how hackers got into Sony’s systems.