Unusual battery drain
Phone getting hot when not in use
Increased data usage without reason
Random pop-ups or ads
Slow performance or frequent crashes
Unknown apps installed
Strange background activity
Microphone or camera indicator turning on unexpectedly
Calls, texts, or notifications behaving oddly
Settings changing by themselves
Device location appearing wrong or shared unexpectedly
Account logins from unknown devices
Friends receiving strange messages from you
SIM card issues or service interruptions
Battery, storage, or permissions showing suspicious use
Security alerts about unknown sign-ins
Phone restarting or shutting down on its own