To know if a phone is hacked, look for these common signs:

• Unknown apps appear that you did not install.
• The phone’s battery drains much faster than usual.
• The phone becomes abnormally slow or overheats.
• Unrecognized calls, texts, or strange activity in call logs.
• Persistent pop-ups and intrusive ads appear unexpectedly.
• Sharp increases in data usage or unexpected charges on bills.
• Websites look strange or get redirected to suspicious sites.
• Unusual noises like clicks or static in calls.
• Receiving verification codes or account alerts not initiated by you.
• Changes to app behavior or settings without your action.

Additionally, using diagnostic tools can help confirm a hack. On Android, Google Play Protect can scan for harmful apps. On iPhone, Apple’s Safety Check helps review access permissions. Using reputable antivirus software can also detect malware or spyware. Certain quick dial codes (like *#21#) can reveal if calls or messages are being forwarded without consent, which may indicate spying. If many of these symptoms are present, consider disconnecting from networks, changing passwords, removing suspicious apps, and possibly performing a factory reset for security.