Kim Jong-Un inspects a cosmetics factory, and senior diplomat Choe Son-hui attends a conference
North Korea has often been implicated in cyber attacks in South Korea and elsewhere but Pyongyang has either ignored or denied accusations of hacking.
“We are almost 100 per cent certain that North Korean hackers were behind the hacking and stole the company's sensitive documents,” Kyung Dae-soo of the main opposition Liberty Korea Party said via telephone.
Daewoo Shipbuilding has built several South Korean warships, including an Aegis-class vessel and submarines.
It was most likely North Korea had obtained blueprints for these, he said.
World War 3: North Korea evacuation drills PROVE Trump is a THREAT
North Korea nuclear disaster will spread radiation across the world
Statues of former Presidents Kim Il Sung and Kim Jong Il at the Mansudae Assembly Hall in Pyongyang
We are almost 100 per cent certain that North Korean hackers were behind the hacking and stole the company's sensitive documents
The hacking was discovered by a division under South Korea's Ministry of Defence in charge of investigating cases of cybercrime, said Kyung, who received a briefing on the investigation.
How sensitive and classified the seized documents were was not known as that was not disclosed by the investigative team, he added.
A spokesman for Daewoo Shipbuilding said she was unaware of the issue until early Tuesday and the company was in the process of confirming the details of Kyung's remarks.
The investigative team came to the conclusion North Korea had hacked Daewoo Shipbuilding because the hacking method was very similar to other attacks that North Korea is thought to be behind, Kyung said.
Hackers in North Korea are believed to have been responsible for a recent cyber heist in Taiwan – the latest in a string of hacks targeting the global SWIFT messaging system.
Earlier this month, another South Korean lawmaker had said North Korean hackers had stolen a large number of classified military documents, including South Korea-U.S. wartime operational plans.
And British authorities said last week they believed North Korea was behind the “WannaCry” ransomware attack in May that disrupted businesses and government services worldwide, including the National Health Service in England.
Kim Jong-un visits cosmetics factory alongside his wife Ri Sol-ju
Sun, October 29, 2017
North Korean leader Kim Jong-un has visited a recently renovated cosmetics factory in Pyongyang
1 of 6
North Korean leader Kim Jong-Un inspecting the Pyongyang Cosmetics Factory, as his wife Ri Sol-Ju looks on