Three major South Korean television broadcasters and two banks were hit in a cyber attack that brought down their computer networks at around lunchtime on March 20.
TV channels YTN, MBC and KBS were hit. Shinhan and NongHyup banks were also affected, although they managed to get their systems up and running later in the afternoon.
South Korea’s government is investigating the cause of the incident. Presidential Office Spokeswoman Kim Haeng said: “We’ve set up a cyber crisis countermeasure headquarters with a task force including civilians, government and military.”
Some people suspect that North Korea, which has targeted its neighbour with hacks in the past, may be behind the problems.
The computer outages come as officials in Seoul are hosting David Cohen, the US Under Secretary for Terrorism and Financial Intelligence, who is in town to discuss economic sanctions on North Korea.