How to know if my iPhone has been hacked or not?

All such messages are scams presented by criminals. Close the offending page and avoid sites that are involved in such bogus advertising tactics. Do not interact with the message or the sender.

https://discussions.apple.com/docs/DOC-8071

Any such message is a lie. Any real crook wouldn't tell you if they had done such a thing. They'd want to keep it a secret as long as possible.

The entire goal of the message was to get you to download and install malware, or to purchase completely worthless AV or VPN software.

You did the right thing not downloading the app they wanted you to get.

All you need to do is delete the message.

As others have mentioned, this is simply an alert from a website. Do not click the links or download anything from them. Additionally, do not call any numbers listed or visit any other sites. Always contact the company (in this case Apple) through their direct channels; such as this forum or Apple's support page.

Safe Web Browsing

In the future I suggest using reputable websites. If you are watching shows over a sketchy website rather than a well-known streaming platform you are more likely to come across this kind of scareware.

If you want, you can delete your website data in Settings > Safari by tapping Clear History and Website Data. Please know this will delete your browsing history and log you out of sites; it will also sync to your other devices if you have iCloud enabled.

This can be a good step to remove any unwanted trackers and cookies. I'd also recommend enabling "Prevent Cross-Site Tracking" while you are in there.

Anti-Virus & Security Software

In regards to downloading software to protect against viruses and malware, iOS has its own security built-in and the operating system is inaccessible to apps without your permission. You can check what permissions you've authorized in the Settings app under Privacy & Security.

Please let us know if you have any other questions.

No. There was never a threat to begin with. The entire message was a lie from beginning to end.

Besides the info from D.I. Johnson, it's even more so on an iPad or iPhone. All third party apps are sandboxed in iOS. They cannot touch any other apps on the device. Not those installed by the OS, or any other third party apps.

The only thing the the 100% worthless AV apps for iOS you can find in the App Store can only scan themselves. They are so useless Apple started removing a lot of them from the App Store a few months ago. Why they ever allowed any at all is as bit of a wonder.

The likelihood of you iPhone being hacked is low. Your iPhone is inherently very secure IF you use a passcode and/or biometrics (face or fingerprint ID) and take care how and where you connect to networks. Unless you are a high-value target like a corporate CEO, president or vp or similar, then you really have little to be worried or concerned about.

Still, here are a couple links to some good info about keeping you iPhone secure.

Use the built-in security and privacy protections of iPhone - Apple Support

iPhone Security Tips: How to Protect Your iPhone from Hackers - Macworld

Why do you think you've been "hacked?" Can you elaborate? Can you also explain what you mean by "hacked?"

You can learn more about Apple platform security here: Apple Platform Security - Apple Support.

No, there is no software that you should download to protect your iPhone.

The same goes for the Mac. Most apps that proffer to clean up, optimize or provide anti-malware protection are less than useful and often cause problems. Best to simply keep your devices updated and practice safe computing habits.

You're welcome. 🙂

Enjoy your iPhone.