Does Factory Reset Remove A Virus From Your Android Phone?


More than 73% of all mobile users use Android devices. With such a broad user base, cybercriminals are constantly searching to exploit this mobile OS with malware. On the other hand, users are always looking for ways to protect and get rid of dangerous viruses, wondering: Does a factory reset remove a virus from an Android phone?

On an Android device, a factory reset will generally remove a virus. The Android operating system uses an app on its recovery partition during a hard reset to restore factory settings. Malicious apps on mobile devices are less prevalent than desktop systems where antivirus software is crucial.

A factory or hard reset wipes your Android phone’s primary memory clean. Contacts, images, apps, movies, files, settings, and other data are deleted. It restores the Android phone to its condition when you first bought it. Viruses, a type of malware, are getting increasingly sophisticated and challenging to detect and eliminate. Want to know when it’s time to do a factory reset? Keep reading, but first, let’s look at the signs of an infected device.

Man touching a virus with one hand while doing a factory reset to remove the virus in the other

Causes Of A Slow Android Smartphone

If your phone has recently become sluggish, there are a few possible causes that aren’t necessarily the result of a virus or malware infection. Here are a few common examples:

  • Outdated hardware
  • Poor internet connection
  • Too many open or installed apps
  • Insufficient storage space on the device
  • Older or unpatched mobile operating system

Note: It’s common for phone models to become slow over time. Not because of the device’s hardware components, but because of the storage and performance demands of newer software programs and operating system upgrades downloaded on your phone. Because those updates are usually designed for newer phone models, older devices might not manage them as well.

Try these four techniques to speed up a sluggish Android phone:

  • Clear the cache
  • Disable live wallpapers
  • Check for app updates and patches
  • Uninstall unused or infrequently-used apps
  • Back up files and photos, secure cloud storage, and clear the phone’s memory
  • Restart your cell phone

If none of the above works and your phone continues to lag, you may need to do a factory data reset as a last resort.

Typically, the factory reset option is listed in the mobile operating system’s Settings page under Reset options labeled as Erase all data (factory reset). Users may find it easier to type “factory reset” into the Settings search field. Since there are many different and customized versions of Android, consult your smartphone manufacturer’s support website to find detailed instructions to perform a hard reset.

Remember: A factory data reset will delete all data from the phone, including viruses, returning it to its original software settings.

If, after a factory reset, your device is still not operating at acceptable performance levels, then it may be time to look at other options.

Man on a park bench with two smartphones wondering if a factory reset will protect against hackers

Does A Factory Reset Stop Hackers?

Doing a hard reset or a factory reset is the best way to un-hack any tablet or phone and counter future attacks.

The hard reset function in most Android phones essentially wipes the whole device, returning it to its original state and hence the name “factory reset.” It eliminates all data, history, contacts, apps, photos, downloads, customized settings, and other user data.

Fortunately, it will also remove all types of malware, including viruses, spyware, ransomware, infected downloads, and other malicious software.

The downside is that all your applications and data will be wiped out. If you’ve been backing up your device, re-installing your apps and restoring data should be somewhat straightforward, albeit time-consuming.

I like calling a factory reset the nuclear option ☢️ because it works for all phones, including iOS devices, and levels the device to a ground state.

Even in scenarios where you’re unsure if your phone is hacked, this approach will give you peace of mind.

Benefits Of A Factory Reset on Smartphones

The benefits to a factory or hard reset are:

  • Removal of viruses or malware
  • Fewer apps to manage and keep updated
  • More privacy with fewer apps synchronizing data
  • Longer battery life with fewer apps using the internet
  • Improved smartphone performance
  • Free up storage space your device clearing junk files
  • Securely wipes old data with full phone encryption enabled
  • Correcting any mistaken OS or app settings
  • Resets permissions for better privacy

Important:

Continuing risky use of your Android smartphone or iOS device will still put you at risk of being hacked again. Manufacturers have put safeguards in place to prevent hacks. Lean on these best practices.

Man on a train using his smartphone now using good habits after he performed a factory reset

Tips For Staying Safe After A Factory Rest

After you’ve gone through the effort of re-installing all your apps and data to your Android smartphone, you’ll also want to do a reset on your personal usage habits to prevent future needs to hard reset.

1. Do a weekly (hard) reboot

These smartphones are fantastic at not requiring frequent resets. I’ve gone weeks or months without power cycling my phone. But, the excellent Techlore YouTube channel reported on a really good idea: Reboot your smart device every week.

Here’s the video (I’ve scrubbed to the point)

While they’re referring to mitigating an issue on Apple iOS devices using a force reboot, the advice holds true by clearing in-memory attacks. There’s no downside from what I can tell, though; I might just execute a standard, soft reboot.

2. Only (re)install apps you need

Apps continuously collect usage data and report home. They are also a source of maintenance as bug fixes need to be regularly installed or patched. The more apps you download, the more opportunities for your phone to become vulnerable.

Avoid installing apps that you don’t intend to use more than a few times. Often, you can simply use the mobile web version of many services instead of the iOS or Android app.

Don’t forget, apps also use up your phone’s memory and persistent storage while edging you towards any data caps or internet usage quotas.

3. Only install apps from Google Play

When you re-install apps after a factory reset, only use the official app store. Apps downloaded through other channels have a higher chance of, in fact, being malicious.

Simple as that.

There’s one exception to getting apps from places other than the Google Play Store that I consider acceptable and even desirable.

4. Advanced users should stick with F-Droid

F-Droid is a collection of free and open-source software (FOSS) apps for the Android platform. There are no monitoring or hidden fees in any of the apps in the library.

This unofficial app store contains software developed by a community of volunteer developers. Since the source code is readily available, coders can audit the programming to discover suspicious activity.

F-Droid has meticulously documented its own external security audits and has a history of correcting issues.

Any apps with potentially non-compliant, undesirable features, or even promoting non-free data are clearly identified. This flagging gives users the transparency and the ability to decide if they’d like to download and install the app.

5. Never sideload apps from untrusted sources

I want to stress the importance of not downloading and installing apps from untrusted sources.

Users frequently ask if it’s ok to get unlocked versions of premium apps from various websites. The answer is an unequivocal no. Sites offering hacked versions of paid apps can inject malware.

Think About It: You’re willingly installing a pre-hacked app to your smartphone, which you use every day and contains all your sensitive data with a live internet connection. Dangerous.

Exception: Some Factory Resets Do Not Remove Viruses

There are types of viruses that cannot be cleared during factory reset.

While this type of malware is rarer, this kind of virus gets into system files or a recovery partition via elevated privileges on the device. After this kind of rootkit attack occurs, even a factory reset cannot reset the device. This is the number one reason not to root or jailbreak a device.

The only viable way to counter this advanced type of malware is to flash the hardware or simply dispose of the cell phone. Hopefully, your smartphone wasn’t too expensive.

Mike Chu

Mike is a web developer and content writer living as a digital nomad. With more than 20 years of devops experience, he brings his "programmer with people skills" approach to help explain technology to the average user. Check out his full author bio by clicking here.

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