How do I know if my iPhone is compromised?

Note that if you have received e-mails, messages, pop-up screens, etc. claiming that your iPhone has been hacked, these are likely scams – packs of lies made up by criminals.

Criminals do this in hopes of getting you to

• Install worthless "security" apps that will do nothing to fix the alleged "problem", or worse
• Give them the information that they need to rip you off directly. They will pretend to be "tech support" people who want to "help" you, but the only "help" you will get if you contact them is help in becoming a victim of their crimes.

Recognize and avoid social engineering schemes including phishing messages, phony support calls, and other scams - Apple Support

U.S. Federal Trade Commission – How To Spot, Avoid, and Report Tech Support Scams

Get help with security issues - Apple Support

Set a passcode on iPhone - Apple Support