Cyber warfare is the study of the various cyber spies infesting computers and systems of defense institutions of a country.
The previous decade has seen some of the highest incidences of cyber warfare. The first one was in 2006 planned by the USA against Iran's Uranium enrichment program.
In 2007, USA and Israel collaborate to develop the most complicated worm ever used. They penetrated Iran's Natanz plant that developed nuclear arsenal. In 2008 all the centrifuges at the plant began crashing. In 2009, outgoing president Bush urged Obama to continue this warfare as it had set back Iran's efforts to develop nuclear weapons by more than 2 years.
By the summer of 2010, almost 130,000 computers globally were infected by this Stuxnet virus that resulted in escape of the virus from the plant. Many of the centrifuges continued to be affected by this virus. But in early 2012, this virus was discontinued. DUQU was developed with high resemblance to Stuxnet, but more powerful.