Cybercriminals use botnets, which are large networks of compromised machines that are centrally managed. These networks are made up of "bots" or "zombie" devices that are generally infected with malware and may be remotely controlled by the attacker. Botnets are frequently employed for a variety of harmful purposes, including the deployment of distributed denial-of-service (DDoS) attacks, the distribution of spam emails, the theft of confidential data, and the commision of extensive fraud. Because of their size and organisation, botnets are powerful tools for hackers that can do a lot of harm. Strong network security, frequent software updates, and user education are all essential components of a multi-layered strategy for defending against botnets in order to keep devices from joining these dangerous networks.
Example
Mirai: A notorious botnet that targeted vulnerable IoT devices. It spread by exploiting weak login credentials, creating a network of compromised devices. Mirai's centralized control directed the bots to launch massive DDoS attacks, causing widespread disruptions. This example highlights the risks of insecure IoT devices.