what is botnet in cyber security

A botnet is a network of computers or other devices that are infected by malware and controlled by a single attacking party, known as the "bot-herder". Each individual machine under the control of the bot-herder is known as a bot or zombie. The bot-herder can command every computer on its botnet to simultaneously carry out a coordinated criminal action. Botnets are created when the bot-herder sends the bot from his command and control servers to an unknowing recipient using file sharing, email, or social media application protocols or other bots as an intermediary. Once the recipient opens the malicious file on his computer, the bot reports back to command and control where the bot-herder can dictate commands to infected computers. Botnets can be used in various attacks that may or may not require additional communication with the command and control server, including data theft, server crashing, malware distribution, spam email generation, and malicious traffic generation for distributed denial-of-service (DDoS) attacks. Botnets are an immense cybersecurity concern to governments, enterprises, and individuals, as they are designed to automate various types of attacks, making them easier, cheaper, and more scalable for cybercriminals to perform.