North Korea's army of trolls

Secretive state employs 3,000 staff to rubbish South Korea and hack South Korean websites

The North Korean state employs more than 3,000 people to spread propaganda, attack neighbouring South Korea in online posts and hack foreign websites - while denying internet access to its own citizens.

That is the claim of South Korea's Chosun newspaper in a report today.

"The north has established a team of online trolls at the United Front Department and the Reconnaissance General Bureau," Ryu Dong-ryul, a researcher at the Police Policy Institute, told Chosun newspaper.

The agents at the two North Korean government departments include 200 focused solely on posting anti-South Korean comments online using identities taken from other South Korean internet users, according to the institute.

Last year, agents employed by the North Korean government posted 41,373 messages, up from 27,090 in 2011, according to the institute. Meanwhile, hackers employed by the North Korean government also break into South Korean websites to post pro-North Korean propaganda.

North Korea trains young computer 'whizz kids' in hacking techniques at top schools in the capital, Pyongyang. The best are selected to spend 10 years at Kim Il-sung Military University, Mirim University or Kim Chaek University of Technology to train as cyber agents.

According to the report, North Korea's "cyber warfare troops develop and distribute apps to subvert South Korean efforts to block pro-North Korean websites and conduct guerrilla-style hacking attacks by constantly changing IP addresses and connecting other sites with pro-North Korean sites".

According to Korea University, some 30,000 North Koreans are employed in cyber and "psychological" warfare against South Korea, with a further 300 personnel trained in such skills every year.

North Korea is arguably the most secretive and tightly controlled state in the world. Led by Kim Jong-un, the country is still technically at war with South Korea, following the 1950-53 Korean War.