A botnet is a remotely controlled network of compromised devices that an attacker can coordinate to perform the same action at once. The devices may be servers, personal computers, or consumer IoT equipment such as cameras and routers. Once infected, each device becomes a “bot” that can be commanded from a control infrastructure.
Botnets matter because they turn many weak systems into a single attack platform. They are commonly used for distributed denial-of-service traffic, spam delivery, credential stuffing, malware delivery, and proxying other criminal activity. In IoT-heavy environments, botnets are especially effective because many devices are exposed to the internet, patched slowly, or remain in service after support ends. Defenders reduce botnet risk by patching devices, changing default credentials, segmenting low-trust equipment, monitoring unusual outbound traffic, and blocking command-and-control connections before large-scale abuse begins.