Washington (CNN) -- China and "probably one or two other" countries have the capacity to shut down the nation's power grid and other critical infrastructure through a cyber attack, the head of the National Security Agency told a Congressional panel Thursday.

Admiral Michael Rogers, who also serves the dual role as head of U.S. Cyber Command, said the United States has detected malware from China and elsewhere on U.S. computers systems that affect the daily lives of every American.
http://www.cnn.com/2014/11/20/politi...rid/index.html