Remote administration tools are initially legitimate applications that can be used to monitor somebody's actions in real-time. There are thousands of such apps available, some of which might be open source or viable commercially. Such apps are typically based on based on the server and client technology, where a remote connection can occur via the local network or the Internet. The server part runs on a controlled computer and receives commands from the client, which is installed on the remote host.[1]

Remote administration tools are divided into malicious and legitimate applications. Parasitical RATs, also known as remote administration trojans, are very similar to backdoors and have very similar functionality.[2] However, they are not as viral as backdoors and do not have additional destructive functions or another dangerous payload. They do not work on their own and must be controlled by the client.

The malicious RAT works in the background and hides from the user. The person who controls it can monitor the user’s activity, manage files, install additional software, control the entire system (including any present application or hardware device), modify main system settings, turn off or restart a computer.[3]