Check for unknown apps on the Home Screen and in the App Library
Review Settings for unfamiliar profiles or device management under General > VPN & Device Management
Check for unknown VPNs under Settings > VPN
Look for unusual battery drain under Settings > Battery
Check for abnormal data usage under Settings > Cellular
Review Safari for suspicious website data under Settings > Safari > Clear History and Website Data
Check for unfamiliar calendar subscriptions under Settings > Calendar > Accounts
Look for unexpected pop-ups, redirects, or browser changes
Review Apple ID devices under Settings > [your name] for unknown devices
Check for unknown email accounts, contacts, or forwarding rules
Update iPhone to the latest iOS version
Remove suspicious apps, profiles, and VPNs
Restart the iPhone
Change Apple ID password
Enable two-factor authentication
Run a security check in Settings > Privacy & Security > Safety Check
Back up important data and erase the iPhone if problems continue