What is a Botnet?
A group of infected devices, usually computers and servers but also IoT devices like cameras or thermostats, that are controlled remotely by a malicious software (malware). Once compromised, these devices can be used to carry out large-scale cyber attacks. The attackers (known as bot-herders) amass these devices, or “zombie computers”, into a network they can control remotely. Botnets can be centralized, or based on the client-server model where a server controls and manages the clients, or they can be decentralized using peer-to-peer (P2P) models where each infected device acts as its own server, making them harder to find and take down.
Attackers use botnets to launch a wide range of automated attacks including distributed denial-of-service (DDoS), password attacks, spam, and cryptocurrency mining. They also exploit vulnerabilities in IoT devices, which can be co-opted into a botnet without the device’s owner even knowing it.
If you’ve been infected with malware that’s turned your device into a bot, your system may become sluggish or it could take longer to open applications. You might also notice a significant increase in data usage or high energy bills as the malware runs background tasks to perform its functions.
Some of the most notorious examples of botnets include GameOver ZeuS, which spoofed web traffic to steal banking credentials and login information from infected systems, Grum, which sent 40 billion emails a day at its peak, ZeroAccess, which targeted Windows OS devices, and 3ve, which was able to bypass antivirus software. Botnets can be disabled by taking down their control centers or removing the malware from infected devices.