A bot is a program, maliciously installed on a computer, that allows that computer and thousands of others to be controlled by attackers. Bots are one of the major problems on the Internet, involved in many spam campaigns and distributed denial of service attacks, as well as allowing attackers to read private information from the computer’s disk and keyboard. Some bots even allow cameras and microphones to be monitored by the attacker. Detecting and removing bots is therefore in the interests of both individuals and internet providers.