A botnet is a network of internet-connected devices, such as computers, smartphones, or Internet of Things (IoT) devices, that have been infected by malware and are under the control of a single attacking party, known as the "bot-herder". Each infected device, known as a "bot," is created when a device is penetrated by software from a malware distribution. The bot-herder can command every computer on its botnet to simultaneously carry out a coordinated criminal action. Botnets can be used to perform Distributed Denial-of-Service (DDoS) attacks, steal data, send spam, and allow the attacker to access the device and its connection. Botnets are usually created by infecting computers with malware, often targeting devices with notoriously poor security, such as IoT systems. The owner can control the botnet using command and control (C&C) software. Botnets are designed to automate various types of attacks, making them easier, cheaper, and more scalable for cybercriminals to perform. Botnets are a significant cybersecurity concern to governments, enterprises, and individuals.