How do I know if my phone has been compromised?
Warning signs include unexplained battery drain, high data usage, unfamiliar apps, overheating, and accounts showing logins you don't recognise.
Last reviewed: 10 June 2026
Explanation
Modern smartphones rarely show a single dramatic sign of compromise. Instead, look for a cluster of subtle changes: your battery draining faster than usual, your phone running noticeably hotter when idle, mobile data consumption spiking without a clear reason, or your phone becoming slow and unresponsive. These can all indicate background processes running that shouldn't be there — including spyware or stalkerware.
Check your installed apps for anything you don't remember installing. On Android, look for apps with broad permissions (location, contacts, camera, microphone) that have no obvious reason to need them. On iPhone, review Privacy settings to see which apps have access to sensitive resources. An unfamiliar app combined with unusual data usage is a strong indicator.
Check your accounts: look at recent login history for your email and social media, review active sessions in your banking app, and check whether your email has forwarding rules you didn't set up. Scammers who gain access to a device often set up silent email forwarding to intercept verification codes.
If you suspect compromise, start with a factory reset (back up essential data to a clean location first). Before restoring, change all your passwords from a different device, revoke access for third-party apps connected to your accounts, and re-evaluate which apps you reinstall.
Common red flags
- Battery life has shortened dramatically with no new apps installed
- Data usage is far higher than usual even when you're not actively using the phone
- Phone feels warm or hot when lying idle
- Unfamiliar apps appear, especially those requesting broad permissions
- Contacts report receiving strange messages or calls from your number
- Accounts show logins from unfamiliar locations or devices
- Your screen lights up or the phone makes sounds when you're not using it
What to do now
- Review all installed apps and remove anything you don't recognise
- Check app permissions and revoke camera, microphone, and location access from apps that don't need them
- Look at recent login history for email, social media, and banking accounts
- Check your email for forwarding rules and connected third-party apps you didn't authorise
- Change your most sensitive passwords from a different device
- Run a reputable mobile security scan (Malwarebytes, Avast Mobile, or built-in device scan)
- If concern remains high, perform a factory reset and restore only essential data
Frequently asked questions
Could my phone be compromised without me installing anything?
Rarely, but possible through unpatched browser or OS exploits. Keeping software updated closes most of those gaps. Stalkerware is often installed by someone with brief physical access to your device.
Will a factory reset remove all spyware?
A full factory reset removes virtually all software-based threats. The exception is extremely sophisticated firmware-level implants used in high-targeted attacks, which are rare for most people.