Signs your phone might have a virus
A phone with a virus usually shows itself through behavior that is noticeably different from normal. The most common signs are a phone that runs much slower than it used to, apps that crash repeatedly, a battery that drains in hours instead of days, or data usage that spikes without explanation. You might also see pop-up ads appearing on your home screen or in apps where they never appeared before, or your phone might get hot to the touch even when you are not using it.
Other warning signs include apps you do not remember installing, text messages or emails sent from your phone that you did not write, or a phone bill that suddenly shows charges for services you never bought. Some viruses also change your phone's settings without your permission — for example, your browser homepage might change, or your location services might turn on by themselves.
Not every slow phone or crashed app means a virus. A phone that is running out of storage space, has too many apps open at once, or has not been restarted in weeks will show many of these same symptoms. Before you assume a virus, restart your phone and check how much storage space you have left.
Key Takeaways
- A phone with a virus typically runs slowly, drains battery quickly, shows unexpected pop-ups, or uses data without explanation.
- Restarting your phone and checking your storage space will rule out the most common causes of slow performance that are not viruses.
- Uninstalling unfamiliar apps and checking your app permissions can remove many threats without needing special software.
- If your phone continues to misbehave after these steps, a factory reset will remove most viruses, though you will lose all data unless you back it up first.
- Your phone's built-in security tools — Google Play Protect on Android and App Tracking Transparency on iPhone — catch most threats before they cause problems.
How to check for viruses on Android
Android phones come with a built-in security tool called Google Play Protect, which scans apps automatically and runs in the background. To check your phone manually, open the Google Play Store app, tap your profile icon in the top right corner, then tap "Manage apps and device." Go to the "Manage" tab and look for any apps you do not recognize or remember installing. Tap any suspicious app and select "Uninstall."
Next, check your app permissions to see what access each app has. Go to Settings, then tap "Apps" or "Application Manager" (the exact name varies by phone brand). Select an app and look at its permissions — if a flashlight app is asking for access to your contacts or location, that is a red flag. Tap "Permissions" and turn off any access that does not make sense for what the app does.
If you want to run a deeper scan, you can download Malwarebytes for Android from the Google Play Store. It is free and will scan your phone for known threats. Open the app, tap "Scan," and let it run. If it finds anything, follow the prompts to remove it.
How to check for viruses on iPhone
iPhones are more resistant to viruses than Android phones because Apple controls which apps can be installed and reviews each one before it appears in the App Store. However, iPhones can still be compromised, usually through phishing links or apps that misuse their permissions.
To check for problems on an iPhone, go to Settings and tap "Privacy." Look at each category — Camera, Microphone, Contacts, Photos, Location — and see which apps have permission to access them. If an app you do not use often has permission to access sensitive information, tap it and toggle the permission off.
Next, check your installed apps. Go to Settings, tap "General," then "iPhone Storage." This shows every app on your phone, sorted by size. Look through the list for apps you do not recognize. Tap any suspicious app and select "Offload App" or "Delete App." Offload removes the app but keeps your data; Delete removes everything.
Unlike Android, iPhone does not have third-party antivirus apps that actually scan your phone — Apple does not allow them to access the system deeply enough. If your iPhone continues to misbehave after removing suspicious apps and checking permissions, a factory reset is the most reliable way to remove a virus.
Steps to take if you find a virus
If you have identified an app that you believe is causing problems, uninstall it immediately. On Android, open the Google Play Store, find the app, and tap "Uninstall." On iPhone, go to Settings, tap "General," then "iPhone Storage," find the app, and tap "Delete App."
After uninstalling, restart your phone completely. Hold down the power button until you see the shutdown screen, then slide to power off. Wait 10 seconds, then turn it back on. This clears temporary files and stops any background processes the virus may have started.
If the problem continues, change your passwords for email, banking, and social media accounts from a different device — a computer or tablet — not your phone. If a virus has been on your phone for a while, it may have captured your passwords. Changing them from another device ensures the virus cannot intercept the new password.
Check your accounts for unauthorized activity. Log into your email, bank, and social media from a computer and look for logins from places you do not recognize or changes you did not make. If you see suspicious activity, contact your bank and email provider immediately.
When to do a factory reset
A factory reset erases everything on your phone and returns it to the state it was in when you bought it. This removes almost all viruses, but it also deletes all your photos, messages, contacts, and apps. Only do this if other steps have not worked and you have backed up your important data first.
On Android, go to Settings, tap "System" or "About Phone," then look for "Reset" or "Factory Reset." The exact path varies by phone brand. Select "Erase all data" and follow the prompts. Your phone will restart and take several minutes to complete the reset.
On iPhone, go to Settings, tap "General," then "Transfer or Reset." Tap "Erase All Content and Settings" and enter your Apple ID password. Your phone will restart and reset itself.
Before you reset, back up your data. On Android, go to Settings and search for "Backup." On iPhone, go to Settings, tap your name, then "iCloud," and make sure "iCloud Backup" is turned on. Both systems will save your photos, contacts, and app data to the cloud so you can restore them after the reset.
How to prevent viruses in the future
The easiest way to avoid viruses is to download apps only from official sources. On Android, use the Google Play Store. On iPhone, use the App Store. These stores review apps before they are published, though not every threat gets caught.
Be cautious with links in text messages, emails, and social media. Viruses often spread through links that look legitimate but lead to malicious websites or fake login pages. If someone you know sends you a link you were not expecting, ask them about it before you tap it — their account may have been compromised.
Keep your phone's operating system up to date. Go to Settings and check for system updates regularly. These updates patch security holes that viruses exploit. On Android, go to Settings and search for "System update." On iPhone, go to Settings, tap "General," then "Software Update."
Turn on automatic app updates so you get security fixes as soon as they are released. On Android, open the Google Play Store, tap your profile icon, tap "Settings," then "Network preferences," and select "Auto-update apps." On iPhone, go to Settings, tap "App Store," and turn on "App Updates."
Frequently Asked Questions
Can I get a virus just by visiting a website?
On modern phones, visiting a website alone is unlikely to infect you. However, clicking a link in an email or text message that takes you to a fake login page or malicious site can compromise your account. Never enter your password on a website you reached through an unexpected link.
Do I need to buy antivirus software for my phone?
No. Google Play Protect on Android and the App Store review process on iPhone catch most threats. Paid antivirus apps for phones do not offer much more protection than what is built in, and some are scams themselves. Stick with your phone's built-in security tools.
What should I do if I think my banking app has been compromised?
Contact your bank immediately from a phone number on your bank statement or card — not a number you find online. Tell them you suspect your phone has been compromised. They can freeze your accounts and help you secure them. Do not wait to see if anything happens.
Will a factory reset remove all viruses?
A factory reset removes almost all viruses because it deletes everything on your phone and reinstalls the operating system fresh. However, some very advanced threats can survive a reset by hiding in your phone's firmware. If your phone continues to misbehave after a factory reset, contact your phone manufacturer or a repair shop.
Can viruses spread from my phone to my computer?
Phone viruses and computer viruses are usually different types of software and cannot infect each other directly. However, if your phone has been compromised, a hacker may have access to your passwords and accounts, which they could use to compromise your computer. Change your passwords from a secure device after removing a virus from your phone.