Bot herders[1] are hackers who use automated techniques to scan specific network ranges and find vulnerable systems, such as machines without current security patches, on which to install their bot program.[2] The infected machine then becomes one of many zombies[3] in a botnet and responds to commands given by the bot herder, usually via an Internet Relay Chat channel.
One of the new bot herders includes the controller of Conficker.
A bot herder usually uses a pseudonym to keep themselves anonymous and may use proxy servers, shell accounts, and bouncers to conceal their IP address thus maintaining anonymity.