
By CHOE SANG-HUN
© 2017 New York Times News Service
SEOUL, South Korea — North Korean hackers stole a vast cache of data, including classified wartime contingency plans jointly drawn by Washington and Seoul, when they breached the computer network of the South Korean military last year, a South Korean lawmaker said Tuesday.
Rhee, a member of the governing Democratic Party who serves on the defense committee of the National Assembly, said he only recently learned of the scale of the North Korean hacking attack, which was first discovered in September last year.
It was not known whether any of the military’s top secrets were leaked, although Rhee said that nearly 300 lower-classification confidential documents were stolen. The military is still unable to catalog nearly 80 percent of the leaked data, he said.
When the hacking attack was found out last year, the Defense Ministry blamed North Korea. But it has acknowledged only that “some classified information” was stolen, saying that revealing more details would only benefit its enemies.
Some South Korean news media, citing anonymous sources, had earlier reported that the leaked data included wartime contingency plans. But Rhee is the first member of the parliamentary committee that oversees the military to disclose similar details.
It remained unclear how much the hacking has undermined the joint preparedness of the South Korean and U.S. militaries, with South Korean officials simply saying that they have been redressing whatever damage was caused by the cyberattack.
As Kim, the North Korean leader, has accelerated his nuclear missile program in recent years, South Korean defense officials have publicly discussed pre-emptive strikes at critical missile and nuclear sites in North Korea and a decapitation operation.
North Korea runs an army of hackers trained to disrupt enemy computer networks and steal cash and sensitive data. In the past decade, it has been blamed for numerous cyberheists and other hacking attacks in South Korea and elsewhere.