Botnet: What it is, how it works, and how to spot and remove it

What it is

A botnet is a remote-controlled crowd of infected devices - PCs, phones, routers, even cameras - all taking orders from a command server. Criminals use these “bots” for spam blasts, DDoS attacks, credential stuffing, malware drops, click fraud, or cryptomining - and they often rent them out as a service.

What you may notice

Internet feels slow; router lights blink nonstop
CPU/GPU runs hot when you’re idle (fans roar, battery drains)
Abuse notices from your ISP / email bounces you didn’t send
Unknown processes, new services, or odd outbound connections

How it spreads

Phishing attachments and fake installers
Weak or reused passwords on RDP/SSH/IoT devices
Unpatched routers, cameras, NAS, or VPNs
Drive-by downloads and malicious extensions

If you suspect you’re part of a botnet

Disconnect from the network (PC and smart devices).
Scan and clean with trusted anti-malware; reboot.
From a clean device, change passwords and enable MFA.
Update router/IoT firmware; disable UPnP, remove risky port forwards, check DNS.
Factory-reset compromised IoT gear; rejoin the network gradually and monitor traffic.

Prevent it

Keep OS, apps, routers, and IoT patched.
Use unique, strong passwords + MFA; never expose admin panels to the internet.
Install software and extensions only from official sources.
Run reputable EDR/AV and consider DNS filtering for known bad domains.

Helpful?

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