Analysts said that North Korea stole billions of dollars through the network attack, a clearer hazard than the nuclear weapons program.

North Korea is under many international sanctions related to the program of nuclear weapons and ballistic missiles, which reaches rapid progress in the leader of Kim Jong-un.

"North Korean nuclear and military programs are long-term threats, but the threat of network attacks from the country is realistic and instantly", Oh Il-Seok, researcher at the Institute of War

North Korea's ability to work globally noticed in 2014 when the country was accused of attacking Sony Pictures Entertainment to respond to the production of "The Interview", satirical film, mocking Kim Jong-

Since then, North Korea is responsible for some famous network attacks, including the item of 81 million USD from the Bangladesh Central Bank, the WannaCry Global Extended Cashemonum attack in 2017, causing about 300,000 machines

North Korea denies every related, describing US allegations of WannaCry as "absurd".

Students wearing the Korean People's Army Uniform (KPa) sitting in front of the computer screen when participating in the classroom at the revolutionary school Mangyongdae, Pyongyang Suburbs in 2018. Photo: AFP.

However, the American Ministry of Justice in February prosecuted three Koreans with a crime of "participating in a large crime plot to conduct a series of destructive nature attacks."

According to the documentation from the National Intelligence Director Office, North Korea's network program "causes spy threats, theft and increasing attacks".

North Korea's network program at least since the mid-1990s, when the leader Kim Jong-il said, "All wars in the coming years will be a computer war."

"They are extremely proficient, professional and able to fulfill advanced attacks," Scott Jarkoff belongs to Crowdstrike Network Security Company reviews.

The rookies of the 121 Bureau are trained in the encryption language and different operating systems at special facilities such as Mirim University, Alumni Jang Se-Yul defected in 2007.

"We are taught that I have to prepare against the US network war ability," Jang said.

Researcher Martyn Williams of Stimson Center, USA, said the network war is particularly attractive to small, poor countries like Korea, capital "outstanding equipment such as aircraft, tanks and systems.

Most sponsored network attacking groups are mainly used for spy purposes, but experts think that is unusual when North Korea deployes network capabilities to gain financial profits.

"Stolen a lot faster and have a much higher profitability than business, especially if you have sex hackers," Williams added.

The announcement in February in February accused three Koreans who stole the amount and electronics worth more than US $ 1.3 billion from financial organizations and companies.

The increase in electronic currencies such as Bitcoin has brought global hackers a series of new profitable goals.

"This allows Korea to easily laundering money to water, out of control of the global banking system. Electronic money is attractive because it is not controlled, borderless and relatively anonymous," he said