Command and Control Server

A Command and Control, or C&C, server is a computer used to coordinate the actions of computers infected by a bot, rootkit, worm or other malicious software (malware) that rely on another computer for instructions and updates.

It may tell infected computers what information to steal, provide targeting information for infected computers to attack or infect, and update existing or install new malware on infected computers.

It may (or may not) also serve as a drop zone for infected computers to upload stolen information.

It does not have to run the same operating system as the computers it controls. Often, a C&C server will be run on a web server that has been compromised or purchased using stolen credit cards.