Security Week [securityweek.com]:
A report published recently by the U.S. Army describes North Korea’s cyber warfare capabilities and provides information on various units and their missions.
The 332-page report, titled “North Korean Tactics,” details North Korean forces and their actions, and one chapter focuses on electronic intelligence warfare, which Pyongyang allegedly uses to collect information on its enemies, deceive its enemies, and launch disruptive and destructive attacks, particularly ones aimed at communication and information systems and infrastructure.
North Korea’s electronic warfare includes both lethal and non-lethal methods. Non-lethal methods include electronic jamming and signals reconnaissance, while lethal methods can include physical destruction of targets supporting its enemy’s decision-making process.
South Korea estimates North Korea's cyberwarfare unit, Bureau 121, has 6,000 members.