Botnet
Botnets are networks of hijacked internet-connected devices, such as webcams and home routers, that have been compromised by malware (or sometimes weak or default passwords) for the purposes of being used in cyberattacks. Botnets can be made up of hundreds or thousands of devices, and are typically controlled by a command-and-control server that sends out commands to ensnared devices. Botnets can be used for a range of malicious reasons, like using the distributed network of devices to mask and shield the internet traffic of cybercriminals, deliver malware, or harnessing their collective bandwidth to maliciously crash websites and online services with huge amounts of junk internet traffic.