Tell Apple
Give this a shot:
1. How to back up your iPhone, iPad, and iPod touch - Apple Support
2. How to erase your iPhone, iPad, or iPod touch - Apple Support
You can stop here and set you iPhone as new without restoring from a back up and see if you still get that "Pop Up" (not a virus). If is is now gone. Repeat step #2 and go to step #3. If it is back again - then it is in your backup, not the fault of Apple. An App you have, data related to that App - perhaps Amazon > should contact their support.
3. Restore your iPhone, iPad, or iPod touch from a backup - Apple Support