14 DAY TRIAL // Korean officials claim that hackers from China stole classified documents from the country's defense and foreign affairs ministries earlier this year by infecting computers with malware.
AFP cites a National Intelligence Service (NIS) spokesperson, according to whom, attackers sent targeted emails in which they impersonated Korean diplomats, presidential counselors and other public figures.
The attached malware posed as official documents, for example, economic forecasts for North Korea.
The intelligence agency has since alerted all government offices about the threat and advised workers to carefully inspect emails before opening them.
According to Lee Jung-Hyun, a member of the South Korean Parliament for the Grand National Party, the security breach involved a considerable volume of classified documents.
Because files were also stolen from the foreign ministry, the country's diplomatic missions abroad were put on guard about the possibility of similar attacks.
Back in August, local papers reported that 1,715 files containing military secrets and older war plans against North Korea, were stolen from the computers of thirteen Army analysts.
There are a lot of similarities between the two incidents, but at this time it's unclear if the security breaches are related.
Back in 2008, the Korean National Security Research Institute announced that trojans discovered on the computer networks of two major military equipment contractors.
One of them produced various types of guided missiles, while the other was responsible with building the country's first ever AEGIS ships.
China and North Korea, especially the latter, are commonly blamed for cyber attacks against South Korean networks, but most of the time investigators can't say with certainty which of them is responsible.
Seoul officials are convinced that the North Korean army has a unit of hackers, who regularly mount attacks from servers in China.
On the other hand, security experts believe that the true origin of most attacks can't be pinpointed accurately, as hackers use compromised computers.