Bot herders are hackers

Hacker (computer security)

In computer security and everyday language, a hacker is someone who breaks into computers and computer networks. Hackers may be motivated by a multitude of reasons, including profit, protest, or because of the challenge...

 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

Bot

Bot or BOT may refer to:-Computing:* Bot, another also name for a Web crawler* Bots , an open-source EDI software* BOTS, a computer game* Internet bot, a computer program that does automated tasks...

 program. The infected machine then has become one of many zombies

Zombie computer

In computer science, a zombie is a computer connected to the Internet that has been compromised by a cracker, computer virus or trojan horse and can be used to perform malicious tasks of one sort or another under remote direction. Botnets of zombie computers are often used to spread e-mail spam...

 in a botnet

Botnet

A botnet is a collection of compromised computers connected to the Internet. Termed "bots," they are generally used for malicious purposes. When a computer becomes compromised, it becomes a part of a botnet...

 and responds to commands given by the bot herder, usually via an Internet Relay Chat

Internet Relay Chat

Internet Relay Chat is a protocol for real-time Internet text messaging or synchronous conferencing. It is mainly designed for group communication in discussion forums, called channels, but also allows one-to-one communication via private message as well as chat and data transfer, including file...

 channel.

One of the new bot herders includes Conficker

Conficker

Conficker, also known as Downup, Downadup and Kido, is a computer worm targeting the Microsoft Windows operating system that was first detected in November 2008...

.

A bot herder usually uses a pseudonym to keep themselves anonymous, and may use proxy server

Proxy server

In computer networks, a proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server...

s, shell account

Shell account

A shell account is a user account on a remote server which gives access to a shell via a command-line interface protocol such as telnet or ssh....

s and bouncers to conceal their IP address

IP address

An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...

thus maintaining anonymity.