Computer networks at two major South Korean banks and three top TV broadcasters went into mass shutdown today, paralysing bank machines across the country and prompting speculation of a cyber attack by North Korea.
Screens went blank at 2pm local time (0500 GMT), with skulls popping up on the screens of some computers a strong indication that hackers had planted a malicious code in South Korean systems, the state-run Korea Information Security Agency said.
Some computers started to get back online more than two and a half hours later.
Police and South Korean officials investigating the shutdown said the cause was not immediately clear. But speculation centred on North Korea, with experts saying a cyber attack orchestrated by Pyongyang was probably to blame.
The shutdown comes amid rising rhetoric and threats of attack from Pyongyang in response to UN punishment for its December rocket launch and February nuclear test. Washington also expanded sanctions against North Korea this month in a bid to cripple the regime’s ability to develop its nuclear programme.
North Korea has threatened revenge for the sanctions and for ongoing routine US-South Korean military drills it considers invasion preparation.