Exclusive - North Korea's Unit 180, the cyber warfare cell that worries the West

FILE PHOTO: Military trucks carry soldiers through central Pyongyang, North Korea April 13, 2017. REUTERS/Damir Sagolj/File Photo

SEOUL (Reuters) - North Korea's main spy agency has a special cell called Unit 180 that is likely to have launched some of its most daring and successful cyber attacks, according to defectors, officials and internet security experts.

North Korea has been blamed in recent years for a series of online attacks, mostly on financial networks, in the United States, South Korea and over a dozen other countries. (GRAPHIC: WannaCry ransomware attack http://tmsnrt.rs/2qIUckv)