Remote Administration Tool

A remote administration tool (RAT) is a piece of software that allows a remote "operator" to control a system as if he has physical access to that system. While desktop sharing and remote administration have many legal uses, "RAT" software is usually associated with criminal or malicious activity. Malicious RAT software is typically installed without the victim's knowledge, often as payload of a Trojan horse, and will try to hide its operation from the victim and from security software.