 Released in 2008, but discovered in 2010, Stuxnet is a computer worm that was designed to attack programmable logic controllers. Stuxnet reportedly compromised Iranian PLCs, collecting information on industrial systems and damaging infrastructure. According to a November 2013 report from BusinessInsider.com, Stuxnet was responsible for destroying one-fifth of Iran's nuclear centrifuges by causing them to spin out of control. The worm exploits four zero-day flaws that are present in some SCADA systems. A zero-day flaw is a vulnerability in an application or operation system that is unknown or developers have not had time to patch. In the case of Stuxnet, the worm targets systems using the Microsoft Windows operating system and networks. Then it began searching for Siemens Step 7 software. If it is able to find the proper vulnerabilities in a given system, then it carries out its exploits. Stuxnet is typically introduced into a system via an infected USB flash drive and then propagates throughout the network. However, with the growing attachment to networked infrastructure and the Internet of Things, there are more access points for individuals who are interested in gaining control of SCADA systems by using worms and viruses like Stuxnet. A good mission-critical operator should be able to run security maintenance and apply best practices to make sure SCADA systems are not compromised in order for the company to continue to run smoothly.