apple pay keeps asking for credit card information for free apps, could it be a virus?

Hi

You cannot download anything from the apps store without a payment method

Go to iTunes main page bottom of page apple I'd click that view I'd Go to manage payments check / add a credit card or buy a iTunes gift card redeem at the bottom of iTunes page.

Cheers

Brian 🇬-1F1E7;

What is the exact text of the message/prompt that you are getting ? And no, it's not a virus (not unless you've jailbroken the phone)