the heads up is appreciated but these pop-ups are more common then web pages themselves. Simply do not respond and report them directly to Apple.
Clear the history and cookies from Safari on your iPhone, iPad, or iPod touch - Apple Support
To report fraud to Apple see this link:
https://www.apple.com/legal/more-resources/phishing/
additionally Apple will NEVER ask your you SSN, thats a dead giveaway of a scam.
Avoid phishing emails, fake ‘virus‘ alerts, phony support calls, and other scams