Unexpected battery drain
Phone running hotter than usual
Sudden spike in data usage
Apps crashing or behaving oddly
New apps you did not install
Pop-ups or browser redirects
Unknown charges on your accounts
Passwords changing without your action
Messages sent from your account that you did not send
Unfamiliar devices signed in to your Apple ID
Calendar events or subscriptions you did not add
Microphone or camera indicator appearing unexpectedly
Settings changing on their own
iPhone restarting, freezing, or lagging often
Security alerts about logins you do not recognize