How to tell if your phone has spyware or a spy app installed

Spy apps — also called spyware or stalkerware — are built to go unnoticed: they read messages, track location or turn on the microphone without the phone's owner noticing. You don't need to be a high-profile target to get one installed: it just takes someone having physical access to your phone for a couple of minutes.

Here are the signs that usually give them away, and how to check for yourself.

Signs your phone might have a spy app

• The battery drains much faster than usual, without a change in your habits.
• The phone overheats even when you're not actively using it.
• Data usage jumps noticeably for no clear reason.
• Apps appear that you don't remember installing, sometimes with generic names or disguised as system apps.
• The phone takes longer to shut down or the screen turns on by itself.
• Someone seems to know things that could only come from your messages, location or calls.

How to check it yourself

• Review the full list of installed apps, including system apps and any hidden from the app drawer.
• Check granted permissions: accessibility, device administrator and screen overlay are the ones spyware most often requests.
• Check whether installing from unknown sources is enabled without you having turned it on.
• Look for processes or apps with odd names or that mimic system applications.

What to do if you find something

Before uninstalling anything, if you think this could end up in a police report or legal proceedings, document it first: screenshots, date, the app's exact name and the permissions it had. Once you have that evidence:

• Change your main account passwords from another device you know is safe.
• Consider a factory reset of the phone once you have the evidence you need.
• If the app came from someone close to you, consider whether you also need a legally valid report.