Hacked apple ID ?
I think I may have been hacked my settings says "review Apple ID phone number & the number it suggests is not known to me ?
iPhone 6, iOS 11
Question marked as
Top-ranking reply
As a precaution, change your password.
What to do after you change your Apple ID or password - Apple Support I suggest doing this before you change your Apple ID or password.
Link to contact Apple Support in the article.
Apple ID has been compromised.