Phishing email

Your iPhone can’t get malware or viruses from a phishing email or text. Actually, there has never been a virus that could infect an iPhone (using the strict definition of “virus” as a self-replicating object that can jump from device to device), and the little malware that exists comes primarily from doing stupid things like jailbreaking your phone or installing apps that don’t come from the App Store.

See→Avoid phishing emails, fake ‘virus‘ alerts, phony support calls, and other scams

Norton, no; all it will do is slow down your phone and make money for Norton. Malwarebytes, maybe; it isn’t an antivirus, it scans your messages and email for spam, so it is useful for that. It was created by one of the forum high-point regulars. I use it on my Mac, but not my phone.