A cyberattack is when digital means are used to infiltrate or damage a compter system. This may involve some form of computer virus, worm or other self-propagating code. It may also involve human attacks, such as phishing. Cyberattacks need not compromise a compter system to cause damage, in particular denial of service (DoS) attacks simply flood a machine with a vast volume of network traffic. The outcome of a cyber attack might be to bring down the system, to extact information, or to leave an infiltarated system available itself to take part in cyberattacks. For example, IOT devices typically have poor security and may be targetted, not to damage them per se, but so that they can be part of a bot army for DoS attacks on the real targets.