Botnet
A network of malware-infected computers ('bots') controlled remotely by a criminal to carry out coordinated attacks such as spam campaigns, DDoS attacks, or credential stuffing.
Also known as: zombie network, bot network
Last reviewed: 1 June 2026
A botnet is a collection of internet-connected devices that have been infected with malware and are under the coordinated control of an attacker (the 'bot-herder'). Individual infected devices, called bots or zombies, typically show no obvious signs of compromise.
Botnets are used to send spam and phishing emails at scale, conduct distributed denial-of-service (DDoS) attacks, perform credential-stuffing attacks against websites, mine cryptocurrency using the victims' processing power, and distribute further malware.
Device owners unknowingly contribute their computing resources and internet bandwidth to criminal operations. Routers, smart-home devices, and poorly secured IoT devices are increasingly recruited into botnets in addition to traditional computers. Keeping all devices patched and using network firewalls reduces the risk of recruitment.
Sources
- FTC — Tech Support Scams — Federal Trade Commission
- CISA — Avoiding Social Engineering and Phishing Attacks — Cybersecurity and Infrastructure Security Agency
- FCC — Frauds, Scams and Alerts Guides — Federal Communications Commission
- AARP — Fraud Watch Network — AARP