What is a botnet attack, and how do you stop one? A botnet (derived from ‘robot network’) is a large group of malware-infected internet-connected devices and computers controlled by a single operator. Attackers use these compromised devices to launch large-scale attacks to disrupt services, steal credentials and gain unauthorized access to critical systems. The botnet command and control model allows the attacker(s) to take over operations of these devices in order to control them remotely. A botnet’s strength is in the number of infected machines it contains. Attackers can control botnets remotely and receive software updates from them, using those updates to quickly shift their behavior.