South Korean banks hit by destructive cyber attack

China identified as most likely source of massive cyber assault.

Unknown hackers temporarily shut down computer networks at South Korean banks and broadcasters in the biggest cyber attack on South Korea in two years.

Computer shutdowns hit corporations such as Shinhan Bank, Nonghyup Bank and several broadcasters. It affected some 32,000 computers, said the government.

Hackers spread malware code through targeted organizations' servers, destroying their computers' ability to boot.

"This is the biggest and most serious cyber attack in two years," said the Korea Communications Commission. It said there haven’t been simultaneous attacks on more than one target since 2011.

All transactions at Shinhan Bank, a unit of Shinhan Financial Group Company, came to a halt yesterday afternoon. Nonghyup Bank said some computers at its main office in Seoul and some branches froze at around 2:15 pm.

Operations at the two banks were back to normal later in the afternoon. Transactions through Internet and mobile banking were unaffected, however.