Despite its poverty and isolation, North Korea has poured resources into a sophisticated cyber warfare cell called Bureau 121, defectors from the secretive state said as Pyongyang came under the microscope for a crippling hack into computers at Sony Pictures Entertainment.
A North Korean diplomat has denied Pyongyang was behind the attack that was launched last month, but a U.S. national security source said it was a suspect.
Defectors from the North have said Bureau 121, staffed by some of the most talented computer experts in the insular state, is part of the General Bureau of Reconnaissance, an elite spy agency run by the military. They have said it is involved in state-sponsored hacking, used by the Pyongyang government to spy on or sabotage its enemies.