Stuxnet
Stuxnet is a notorious computer worm which was designed to attack centrifuge systems used to refine nuclear material. It is best known for its successes in this endeavor in the Islamic Republic of Iran. These successes made Stuxnet the first known cyberweapon.
History
In June 2010 a security company VirusBlokAda detected this malware and gave it the name "Rootkit.Tmphider."[1] Symantec then named it "W32.Temphid," but later changed the title again to "W32.Stuxnet." Unlike some other malware like Conficker, Stuxnet did not give itself a name. Instead, the name was derived from common references in the worm. The first part of the name, "stu," comes from the ".stub" file extension, and the second part, "xnet", comes from the "MrxNet.sys" file.[2]
Origin
The writer of this malware is not known, but the complexity of it and the amount of research which went into it suggests to most that it was designed by an organization or government. It used a number or zero day exploits (vulnerabilities which had not yet been found) which implies a powerful entity was behind it. Since the United States and Israel would probably be at the greatest risk if Iran does achieve nuclear capabilities, it is generally suspected that one or both of these governments where involved.
Details
The Stuxnet worm spread like all other worms, on its own without human action. It jumped from system to system, checking for Siemens industrial control systems, which where used by several uranium refineries in Iran. If the systems where not detected, it would try to spread to other computers, but not harm its new host. Only if these systems where present would it go to work, causing the equipment to malfunction while the monitors displayed false information.
The targeted refinery systems where air-gaped, that is, not connected to the internet. Therefore, the malware needed to be hand delivered. In such cases, an infected flash drive is often left outside of the facility, and a curious or well-meaning individual will connect it to a computer inside to see the contents. Once connected, it will infect the computer, and begin to spread.