What is a Botnet?

A Botnet is a network of many computers or devices that have been infected with malware or a virus and are controlled without their owner's knowledge by a "botmaster." Such networks are used by cybercriminals for various illegal activities, such as DDoS attacks, sending spam, data theft, and other cybercrimes. Each device included in a botnet is called a "bot" or "zombie."

The process involves infecting devices with malware, establishing command and control (C&C) over them via a central server, and then using the network of bots to carry out attacks or illegal activities.

Botnets are used for various malicious activities, including DDoS attacks, spam distribution, keylogging and data theft, cryptojacking (using infected devices' processing power to mine cryptocurrency), phishing attacks, and click fraud.

Protection measures include using updated antivirus and antimalware software, keeping all software updated, using a firewall, practicing safe email habits, using strong passwords, and monitoring for suspicious device activity.

The text mentions prominent examples like the Mirai botnet (used for large-scale DDoS attacks), the Zeus botnet (used for keylogging and data theft, primarily banking trojans), and the Conficker botnet.