“My battery drains fast, am I hacked?” — almost never. Most scary symptoms have boring explanations. But a few signs genuinely point to compromise. Here’s how to tell the difference and what to do.

Signs that genuinely matter

Apps you didn’t install appearing on the phone.
Camera or microphone indicator turning on when you’re not using them.
Settings changing by themselves — app permissions granted, two-factor turned off.
Being logged out of accounts, or login alerts from unfamiliar locations.
Unexpected charges or premium-SMS activity on your bill.
Pop-ups and redirects appearing outside the browser.

Signs that usually mean something ordinary

On their own, these are almost always a normal fault, not a hack:

Fast battery drain — usually a background app or an aged battery (see our battery guide).
The phone running warm or slow — usually heat, storage, or a heavy app.
Occasional ads in free apps — that’s the app, not a hack.

Worry when you see the first list, especially several together — not when a three-year-old phone’s battery is simply tired.

What to do if you see the real signs

Remove unfamiliar apps immediately. On Android, boot into Safe Mode first if an app won’t uninstall.
Change your important passwords from a different, trusted device — email first (it’s the reset hub for everything else), then banking. Don’t do this on the suspect phone.
Turn on two-factor authentication for those accounts.
Check account activity / active sessions in your email and Google/Apple account, and sign out unknown sessions.
Update the OS — many compromises rely on unpatched holes.
If in doubt, back up your data and factory reset the phone — the cleanest way to remove persistent malware.
Contact your bank if you see any unfamiliar charges.

How phones actually get compromised

Usually not by mysterious “hacking” but by sideloaded apps, fake apps, phishing links, or someone with physical access installing stalkerware. Sticking to official app stores, not tapping links in unexpected messages, and keeping the OS updated prevents the large majority.

Frequently asked questions

Can someone hack my phone just by calling me?

For ordinary users, no — a normal call can’t install anything. The real risks are links you tap, apps you install, and reused passwords.

Do I need a phone “antivirus” app?

Generally no on iPhone, and modern Android has Play Protect built in. Good habits beat another app. Be wary of “antivirus” apps that themselves nag and track.

What is stalkerware?

Hidden apps installed by someone with physical access to monitor you. A factory reset removes it; if you’re in an unsafe situation, seek support before tipping off the person.

Signs your phone might be compromised (and what to do)