Another wave of powerful cyberattacks started in Europe today, and so far it's affected companies in India and the United States. In Ukraine, it shut down the major airport and the Chernobyl nuclear power plant. Mikko Hyppönen, a cyber security expert in Helsinki, Finland, says the virus, which already has spread for six to seven hours, will continue infecting sites all over the world because there is nothing in the code to kill it.