What is a botnet?
The term bot is short for robot. Criminals distribute malicious software (also known as malware) that can turn your computer into a bot (also known as a zombie). When this occurs, your computer can perform automated tasks over the Internet, without you knowing it.
Criminals typically use bots to infect large numbers of computers. These computers form a network, or a botnet.
Criminals use botnets to send out spam email messages, spread viruses, attack computers and servers, and commit other kinds of crime and fraud. If your computer becomes part of a botnet, your computer might slow down and you might inadvertently be helping criminals.
For more information, see How to better protect your PC with botnet protection and avoid malware.