Generally when we talk about “botnets” we’re talking about networks of devices infected with malware that serve an unintended (and usually malicious) purpose for an unknown external agent, one who controls the network with a centralized “command and control” service. An example would be the Srizbi botnet, formed by Windows machines infected

Source: Hot Hardware – Google Gimps Huge Glupteba Botnet That Infects A Million Windows PCs With Malware