Check for sudden battery drain
Check for unusual data usage
Check for overheating when idle
Check for unknown apps
Check for apps with strange permissions
Check for pop-ups or ads outside the browser
Check for frequent crashes or slow performance
Check for calls, texts, or emails you did not send
Check for unexpected password reset emails or login alerts
Check for unknown devices signed into your accounts
Check for settings changes you did not make
Check for microphone, camera, or location indicators turning on unexpectedly
Check for browser redirects or changed homepage/search engine
Check for new admin, accessibility, or device management apps
Check for bank, social media, or email account activity you do not recognize
Check for security warnings from your antivirus or phone security app
Check whether your phone restarts, freezes, or behaves oddly without reason
Check your installed app list for anything unfamiliar
Check your call forwarding and SMS forwarding settings
Check whether your contacts received messages you did not send
Check whether your phone number or SIM shows unusual service issues