Battery drains much faster than usual
Phone gets unusually hot when not in use
Data usage spikes without explanation
Apps open, close, or crash by themselves
Unknown apps appear on the phone
Pop-ups or ads appear outside the browser
Calls, texts, or notifications are missing or strange
Phone restarts, freezes, or slows down unexpectedly
Microphone, camera, or location icon activates unexpectedly
Contacts receive messages you did not send
Passwords or account logins stop working
Security settings change without your action
Browser homepage or search engine changes on its own
Phone shows unusual background activity
Device is rooted, jailbroken, or has unknown admin access
Bank or email accounts show suspicious logins
Antivirus or security app is disabled without reason
SIM card stops working or shows no service unexpectedly
Strange charges appear on your phone bill
Phone works normally in Safe Mode but not in regular mode