The South Korean government has admitted that its cyber military command was hacked last month by injecting malicious codes into one of its main routing servers. However, authorities say the possibility of any data theft is low as the military intranet was not connected to the targeted server.

"A malicious code has been identified and it seems to have taken advantage of the vulnerability of the routing server," Kim Jin-pyo, a lawmaker told Yonhap news agency. "In a cautious measure, the server has been separated from the network."

The targeted server was a security buffer for computers that the military had specifically allotted for Internet-connection purpose. Nearly 20,000 military computers were connected to the server at the time of attack.

A formal investigation has begun into the hack and its origin. Among those suspected, the first finger is being pointed at the North. The South has accused the North of focusing on strengthening its cyber warfare capability over the years and in the past blamed them of various hacks like the Nuclear plant and subway system hacks.

"North Korea began to train its cyber warriors while developing nuclear arms in the early 1990's and now commands 1,700 highly skilled and specialised hackers," Cho Hyun Chun, chief of South Korea's Defence Security Command had said earlier.

To prevent these breaches Seoul has established its own defence cyber command, where it trains its brightest minds, to take on what it calls sophisticated state-sponsored hackers.