Stuxnet, Wiper and Flame: The viruses that pose a threat to states
MPs have warned that UK armed forces are so dependent on information technology that their ability to operate could be "fatally compromised" by a cyber attack. Other countries have faced virus attacks, often from other states.
Stuxnet
Perhaps the best known cyber attack on a nation, Stuxnet targeted Iran's uranium refining systems.
Research has suggested that although the Stuxnet virus was felt in Iran in 2010 it had origins back to 2007.
Stuxnet is also related to Duqu (see below) and it could be that the two were created to work simultaneously, it also has similarities to Flame.
Flame
According to Russian security firm Kaspersky Labs, Flame has been operating since August 2010 but was not uncovered until May 2012. The company told the BBC last year that it believed the attack was state-sponsored, but could not be sure of its exact origins.
Flame is a computer virus that contains a sophisticated attack toolkit, and which is a lot more powerful than previously encountered malware such as Duqu according to ITU (International Telecommunication Union.
The virus collected huge amounts of sensitive data.
Flame has been reported in North America and Europe but affects have also been felt in:
Iran
Israel
Sudan
Syria
Lebanon
Saudi Arabia
Egypt
Wiper
Wiper is still under investigation by both Kaspersky Labs and ITU and is named for its primary trait - destroying and wiping files.
Wiper may have been responsible for wiping hard disks in an attack targeting oil facilities in western Asia.
Wiper also spawned copycats such as Shamoon, but little is known about it to date.
Duqu
Duqu has been described as a sophisticated Trojan (a programme which looks like a benign file but which hides the virus) and is believed by Kaspersky Labs to have been written by the same people who created Stuxnet.The Lab says that Duqu acts as a way to extract information from infected systems. It differs from Stuxnet in that it was created to extract intelligence rather than targeting computer systems which control industrial processes in the real world.
Gauss
Targeting the Middle East Gauss was designed to steal sensitive information and was discovered during the ITU investigation in to Flame.
It is believed that the malware has been operating since September 2011 and was uncovered in June 2012. It is possible that tens of thousands have been infected, while a much lower figure than that believed to be infected by Stuxnet it is significantly higher than those subject to Duqu or Flame.
Kaspersky Labs describes Gauss as "a complex, nation-state sponsored cyber-espionage toolkit designed to steal sensitive data, with a specific focus on browser passwords, online banking account credentials, cookies, and specific configurations of infected machines"
Kaspersky Labs is a private Russian company which has often worked with the ITU, providing services on a non-commercial, pro-bono basis.