Malwarebytes employee reports receiving multiple calls claiming to be from Apple Support and asking for her credentials. iCloud accounts double as Apple IDs, which can be used to make purchases from the Mac App Store, iOS App Store and online and brick-and-mortar Apple Stores. Never give out your credentials to anyone, not even an Apple representative, and never log in with your Apple ID to any site you reach by clicking a link in an e-mail message. The correct response if you think your iCloud account has been hacked, is to go to Apples website and log into the Apple ID account page.”]
Source: https://blog.malwarebytes.com/cybercrime/2017/04/icloud-support-scams/