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    Malware & infrastructureCybersecurity glossary

    Botnet

    A network of infected machines an attacker controls remotely to send spam, launch denial-of-service attacks or distribute malware.

    Full definition

    A botnet is a network of infected devices, computers, servers, routers, cameras, that an attacker controls remotely without their owners knowing. Each recruited machine, called a bot or zombie, executes orders received from the operator's command and control infrastructure.

    Botnets are the heavy machinery of cybercrime: they send massive phishing and spam campaigns, launch distributed denial-of-service (DDoS) attacks, run credential stuffing at scale and distribute other malware. Operators also rent that capacity to third parties as a service.

    For a company the risk is double: being targeted by a botnet, or being part of one, contributing machines that attack others and burn the network's reputation. Patching, changing default passwords and monitoring outbound traffic reduce both fronts.

    Related terms

    From definition to data: measure your company's human risk

    Fensivo detects leaked credentials, simulates real attacks and validates with retests that behavior changed.