Pop-ups, strange apps, or a phone acting up often point to a harmful app. These steps help you find and remove the cause.

Signs of a problem

• Pop-up ads appear everywhere, even outside your browser.
• Your browser home page changes or sends you to sites you did not choose.
• Apps you do not remember installing show up.
• Your phone slows down, freezes, or crashes.
• Friends get messages or posts you never sent.

First, rule out a fake alert

A website pop-up saying “Your phone is infected” is often a scam. Do not tap it or call any number it shows. Close the browser tab. Learn more in How to Spot a Tech Support Scam.

Clean up your phone step by step

1. Pause sensitive logins. Stay out of banking and email on this phone until the problem is fixed.
2. Run a Play Protect scan. Open the Google Play Store app. Tap your profile icon, then Play Protect, then Scan. Remove any app it flags.
3. Remove apps you do not recognize. Open Settings, then Apps. Uninstall anything you did not install or no longer trust.
4. Still having trouble? Use safe mode. Safe mode turns off downloaded apps. If the problem stops in safe mode, a downloaded app is the cause. Remove recent apps one at a time, and restart normally after each one. The steps to enter safe mode vary by phone maker, so check your maker’s support site.
5. Update everything. Install system updates in Settings and app updates in the Play Store.
6. Change your passwords. Use a different, trusted device. Turn on two-step verification for your email and bank.
7. Last resort: factory reset. A reset erases everything on the phone. Back up your photos and contacts first. Do not reinstall the app you suspect.

Keep it from happening again

• Install apps from the Google Play Store only.
• Keep Play Protect turned on. It checks apps before you install them.
• Read the permissions an app asks for. A flashlight app has no need for your contacts.
• Skip links in texts you did not expect. See How to Avoid Dangerous Links.

Sources: Federal Trade Commission. (n.d.). How to recognize, remove, and avoid malware. Consumer Advice.
Google. (n.d.). Find problem apps by rebooting to safe mode on Android. Android Help.
Google. (n.d.). Use Google Play Protect to help keep your apps safe and your data private. Google Play Help.