In 2010 the Pentagon set up the US Cyber Command to coordinate and conduct both defensive and offensive military operations in cyberspace. The Stuxnet virus, designed to destroy Iran’s uranium-enriching gas centrifuges, and first identified that same year, is believed to have been a demonstration of the US’s abilities to wage war by attacking enemy computer systems. There have already been calls for the White House to launch cyber operations against Syria. Targets could be military, such as air defences, or critical infrastructure, such as the electricity grid or financial systems. Some cyber attacks use malware (malicious software) to gain access to enemy systems in order to either steal sensitive information or gain control of them. Information can be harvested using key logging software that tracks keystrokes, for example. Spoofing involves forging packets of data so that they look as if they come from legitimate sources. There are also data-driven attacks. A common form is the denial of service (DDOS) attack which aims to cripple systems by bombarding them with data, usually using bot-nets – large numbers of compromised computers.