Exclusive: North Korea’s Unit 180, the cyber warfare cell that worries the West
That attack was conducted from a base in China, according to Simon Choi, a senior security researcher at Seoul-based anti-virus company Hauri Inc.
Malaysia has also been a base for North Korean cyber operations, according to Yoo Dong-ryul, a former South Korean police researcher who studied North Korean espionage techniques for 25 years.
http://www.reuters.com/article/us-cyber-northkorea-exclusive-idUSKCN18H020