The computer worm Stuxnet is a malicious program discovered in 2010, which was specially developed to attack the SCADA system Simatic S7 from Siemens. It was used in a targeted way to manipulate frequency converters in critical infrastructures. The computer worm drew public attention after it was identified as being the malware responsible for disruptions to the Iranian atomic program. Stuxnet is considered extremely complex malware that spread slowly and very selectively in the control network of the nuclear systems over several years. Accordingly, the infection already took place in 2007. The principal actor is still unknown to this day. However, development costs have been estimated to be at least $100 million.