Shadow IT is a real problem in many organizations. Behind this term, we speak about pieces of hardware or software that are installed by users without the approval of the IT department. In many cases, shadow IT is used because internal IT teams are not able to provide tools in time. Think about a user who needs to safely exchange files with partners and no tool is available. A change request will be created to deploy one but, with the lack of (time|money|resources), the project will take time. Unfortunately, the user needs the tool now, so an alternative path will be used like a cloud file sharing service.
Article Link: InfoSec Handlers Diary Blog