Botnet

A Botnet is an aggregate collection of a large number of computer systems, often dispersed around the world, that have each been silently compromised for on-demand control by a single attacker or organization for use in illicit activity.

Botnets are most commonly used for distributed denial-of-service (DDOS) and persistent or long-term brute force attacks, though they may also be used for cryptocurrency mining or the sending of unauthorized commercial email.

When a botnet attack is launched, the "zombies" (individual computer systems under the botnet's control) perform the work of conducting the illicit activity, together providing a large amount of computing and network power that is difficult to trace, isolate, or constrain.