A botnet is a collection of compromised computers and other devices that can be used by hackers, criminals, and bad actors to carry out attacks on websites, devices, and technology across open, public networks. They recruit unprotected devices into a botnet network using trojans and malware and then exploit botnet machines to attack other internet resources.

Terms related to Botnet: Hacker, Attacker, Attack Vector, Denial of Service (DoS) Attack, Distributed Denial of Service (DDoS) Attack, Internet of Things

Botnets are sophisticated networks of compromised computers that are used by hackers for further cybersecurity attacks. A computer or other device becomes part of a botnet by unintentionally installing malicious code like a virus or trojan. Then, unknown to the user, a hacker can take control of the device to cause further harm. Botnets can be created from standard laptops or PCs, smartphones, Internet of Things (IoT) devices, or potentially any internet-connected technology.

Botnets are used in several types of unethical and criminal behavior including a denial or distributed denial of service attack where multiple requests are made to a website in a short period of time to overload the server and prevent legitimate access. Botnets can also send out large quantities of spam email through a user’s machine or generate large amounts of fake traffic to a website for financial gain (for example through automatically clicking on pay per click ads).

Users and security teams can protect against devices becoming part of a botnet by ensuring that robust antivirus and firewall software is in place. Additionally, vulnerability scanning and penetration testing can help to locate and patch unsecured machines that may be targeted by a botnet malware attack.