Virus notice received on my Iphone

This is not a virus.

It's a scam message saying that there're viruses found.

Double tap the Home button, swipe upwards on the Safari preview.

Go to Settings - Safari - Clear History.

Restart Safari.

Phony "tech support" / "ransomware" popups and web pages

One way to erase viruses, I believe, is by Erasing Everything on your phone. (It Is Called Factory Reset)

Bless You, any further questions, I can help.

-Angel B. Grant