Many iPhone 6s/7 and iPhone 8, iPhone X user are seeing a pop up scam while browsing different websites on their iPhone safari browser. The issues is even reported with latest iPhone models like iPhone 8/X with iOS 11. The pop up scam keep getting a popup in Safari stating that user have won an Amazon gift card etc. The scam pop say like “Apple user ... you have won an Amazon card”. and sometimes pop up message is like " congratulation Amazon user ...".Pop-up/redirect will not go away and is continuously happening. Pop up has a "close" button, but if you click on it or anywhere on the screen, it will take you to the scam site where it asks to answer stupid questions for a chance to win fake prizes. This even happens in private browser mode, and phone is extremely slow. The amazon/gift card scam pop issue is regardless of which site is opened and even happening with Yahoo email links, Facebook on safari etc.
iPhone users have tries with the Popup Blocker on along with the Fraudulent Website warning on, cleared browser cache, pop-up blockers are on, hard reset phone, but after all of this nothing seems to help to remove this pop issue. But it’s not a popup but a redirect. So, no - popup blocker is not going to work. Many users even tried to download antivirus but did not seems to work all the time.
Actually this spamy ads that hijack your browser through deep linking. Clearing browser cache and restarting Safari or Chrome won't help. It cab be due to poorly coded websites or website owner not paying attention to what is being published on their website. Resulting letting web browser exposed to many threats to store malicious data for such pop issue.
However you may try below solution to fix the pop up issue on iPhone:
Fix 1: Clear websites data
Goto to the safari Settings in your iPhone—>safari—>advanced—>website data—>search and delete the site there or clear them all out. Delete anything suspect, such as unknown domains, ad-sites, anything from yahoo or yimg, domains with random characters. This should stop this pop up.
Fix 2: Delete website pop up pages
Go to the lower right corner of your screen where the little boxes are and tap to go to the storage pages of web pages and then tap the “X” to delete the pop up page. You have to do every time you see this issue. But this should stop and linked pop up to specific websites.
Fix 3: Use Brave Browser