Woori Bank
The attacks on all six organizations derived from one single entity. The networks were attacked by malicious codes, rather than distributed denial-of-service (DDoS) attacks as suspected at the beginning. It appeared to have used only hard drive overwrites. This cyberattack “damaged 32,000 computers and servers of media and financial companies.” The Financial Services Commission of South Korea said that Shinhan Bank reported that its Internet banking servers had been temporarily blocked and that and NongHyup reported that operations at some of their branches had been paralyzed after computers were infected with viruses and their files erased. Woori Bank reported a hacking attack, but said it had suffered no damage. Computer shutdowns also hit companies including the Korean Broadcasting System, Munhwa Broadcasting Corporation, and YTN.