Hello sochun2424,
Thanks for using Apple Support Communities.
I see that you are getting a pop up message asking to change your iPhone's passcode within 60 minutes. I know how important it is to make sure that the messages you receive are legitimate. I'll be more than happy to assist you with this.
If this iPhone is used for a business or work, you may have Mobile Device Management installed on the iPhone. If there is a profile installed, it could have passcode enforcement that requires the passcode to be changed after a specific time. This can also happen if there is an Exchange ActiveSync account (e.g. Hotmail, Outlook, Windows Live, Gmail configured as Exchange) that has a passcode enforcement.
If one of these are in use, please contact whomever supports that MDM implementation (i.e. IT Department) for further assistance.
Additionally, more information can be found on the following website:
iPhone in Business
Best Regards.