Remote administration tools provide full control of systems within your network or originating from your network.
Remote administration tools / desktop sharing tools can be used with good intent, but can also be used to dangerous effect by malware and consequently used in social engineering attacks. Well-intended actions, such as remote working programmes, are often facilitated via remote administration tools but doing so opens up a gap in your security environment. Certain tools, regardless of popularity, can be detected based on 3rd party IP-addresses; others can be detected via their port number. TeamViewer, for example, can be detected even though no connection is in-place.