Advanced persistent threat
An advanced persistent threat (APT) is a stealthy threat actor, typically a state or state-sponsored group, which gains unauthorized access to a computer network and remains undetected for an extended period. In recent times, the term may also refer to non-state-sponsored groups conducting large-scale targeted intrusions for specific goals.
A diagram depicting the life cycle staged approach of an advanced persistent threat (APT), which repeats itself once complete.
Stuxnet is a malicious computer worm first uncovered in 2010 and thought to have been in development since at least 2005. Stuxnet targets supervisory control and data acquisition (SCADA) systems and is believed to be responsible for causing substantial damage to the nuclear program of Iran. Although neither country has openly admitted responsibility, multiple independent news organizations recognize Stuxnet to be a cyberweapon built jointly by the United States and Israel in a collaborative effort known as Operation Olympic Games. The program, started during the Bush administration, was rapidly expanded within the first months of Barack Obama's presidency.
Siemens Simatic S7-300 PLC CPU with three I/O modules attached
Anti-aircraft guns guarding Natanz Nuclear Facility