South Korea's three main broadcasters and two of its major banks were paralyzed on Wednesday by a massive outbreak of malicious code that crashed and displayed "skulls" on some computers, thought by many to be a retaliatory cyberattack from North Korea. The television channels KBS, MBC, YTN and the banks Nonghyup and Shinhan Bank had their computer systems simultaneously shut down at around 2 p.m., with employees unable to boot up their computers or access the internet; by 4 p.m., the systems had been restored. Media outlets were able to continue broadcasting, but Shinhan found that its internet banking and some ATMs were rendered inoperable. The South Korean government has launched an investigation and upgraded its information operations condition; North Korea has been threatening to launch a cyberattack since last week, when it accused the U.S. and South Korea of hacking computers in Pyongyang. The hack is believed to have come through services provided by LG. [BBC | Korea Herald | AJE]