Three Japanese computers were part of a large cyber attack on South Korean government websites' internet security earlier this year, according to a National Police Agency investigation, news sources say.
South Korean law enforcement said March denial of service attacks, in which access to government websites was hindered by a flood of page requests and thought to be the work of North Korea, was launched from over 740 computers in about 70 countries. Computers, including three in Japan, were infected with viruses that allowed a distant server to order them to start the attack, reports say.
The National Police Agency said this is the first known instance of a personal computer in Japan being used for cyber terrorism. They believe two servers and one personal computer were accessed without knowledge of their owners.
All three systems were running older operating systems without antivirus software, according to sources. The owners have been advised by authorities to improve their computer and internet security. South Korean officials said the attack was similar to an attack in 2009 when the North Korean communications ministry launched an attack via a Chinese IP address.