South Korea put its military on alert after a large-scale cyber attack, and investigators suspect North Korea.  A spokesman for South Korea’s President said Seoul has formed a “cyber crisis countermeasure headquarters” to deal with the new threat.

Three banks say they’ve restored computer operations, and three television stations are still broadcasting but could not say when their systems would be back up and running.

Defense Ministry spokesman Kim Min-seok said “We cannot rule out the possibility of North Korean involvement, but we don’t want to jump to a conclusion.”

South Korea is one of the world’s most-wired societies and has been increasingly worried about hacks from the North. 

Last week, North Korea complained it was the target of an alleged U.S-based cyber attack.