SEOUL, March 20 (Yonhap) -- South Korea's military has upgraded its information surveillance status as investigations were under way to figure out potential causes of network crashes at major broadcasters and banks on Wednesday, the defense ministry said.

   The latest move comes as servers at television networks YTN, MBC and KBS as well as two major banks Shinhan Bank and Nonghyup were paralyzed. Investigations are currently under way to figure out possible causes of the outages.

   Defense minister Kim Kwan-jin convened an emergency security meeting at around 3 p.m. to review the military network system and upgraded its the current status of Information Operation Condition (INFOCON) from Level 4 to Level 3. The five-tier threat level system has been used by the military to defend against a computer network attack.

   "Currently, the military network is operating normally," ministry spokesman Kim Min-seok said. "There were no (hacking) attempts from outside."

   While initial speculation centered on a potential hacking attack by North Korea, which has hacked South Korean institutions before, Kim said it was not immediately known whether the North was involved in the alleged cyber attack, though he did not exclude the possibility of the communist nation's involvement.

   "The military will cooperate with other related agencies to figure out the causes of the network paralysis," Kim said.

   ejkim@yna.co.kr
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