What it is
A botnet is a distributed network of devices—servers, laptops, mobile phones, IoT appliances—that have been infected with malware granting remote command-and-control to an operator. Individual bots often enter the network through phishing, drive-by downloads, credential stuffing, or exploitation of unpatched services. Once enrolled, each device contacts a control infrastructure that may use centralized servers, peer-to-peer meshes, or even social media channels to receive instructions. Operators can dynamically update payloads, rotate infrastructure, and rent access to other criminals. Modern botnets emphasize stealth by using encrypted communications, domain generation algorithms, and modular components that adapt to defensive countermeasures. Because many infected devices sit behind residential or corporate networks, mitigation requires coordination among ISPs, CERTs, and affected organizations to disrupt command infrastructure and remediate endpoints. Botnets underpin a wide range of cybercrime economies, from distributed denial-of-service services to click fraud, credential cracking, and ransomware staging.
Why it matters
Even a small business can unwittingly host bots that participate in attacks against partners or customers, exposing the organization to liability and reputation damage. Botnet traffic can saturate network capacity, inflate cloud bills, and serve as a pivot point for deeper intrusions.
How to reduce risk
- Enforce rigorous patch management and antivirus coverage on all endpoints, including servers and IoT devices.
- Monitor outbound traffic for anomalies such as beaconing, unusual DNS queries, or encrypted tunnels to unknown hosts.
- Implement rate limiting and web application firewalls to diminish the impact of bot-driven credential stuffing or scraping.
- Collaborate with hosting providers and law enforcement when indicators of botnet compromise are detected.