Why A Factory Reset Won't Remove All Viruses (Do This Instead)

Does Resetting Your Phone Help With Viruses?

Yes. Performing a factory reset on your mobile device can help combat viruses by removing infected files and curing malware infections — but it won’t always be enough to completely remove all malicious software from your phone. 

Many viruses can survive a factory reset by hiding in hard-to-reach locations on your phone, such as deep within your device’s settings and preferences. 

In recent years, cybersecurity researchers have found that [*]:

Viruses and malware targeting your device’s firmware — programs embedded deep in your device’s hardware — are becoming more of a threat.

If you think your phone has a virus, a factory reset is a good first step to take. But you may need to take more drastic measures to completely clean up an infected device.

In this guide, we’ll explain what a factory reset can and can’t do, how to reset your iOS and Android devices to their factory settings, and which methods are best for detecting and removing viruses from your mobile devices.

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How To Tell If Your Phone Has a Virus

According to the latest research, nearly nine million new malware programs appear every month [*] — and hackers are always looking for new opportunities to use these programs against you.

Unfortunately, there are more ways than ever for your phone to become infected with spyware, ransomware, and other viruses — from clicking on links in phishing scams to downloading infected apps, giving up account passwords to hackers, and visiting fake websites. 

Once your phone has been infected, scammers can steal your sensitive information, break into your online accounts, or even spy on you by using your phone’s camera and microphone. 

Here are some of the most common warning signs that your phone has been hacked or has a virus:

• Your phone seems slow, sluggish, or is acting strangely. Viruses can hog your device’s resources, causing it to slow down or even stop working properly. If your iPhone or Android device suddenly slows down, heats up, makes odd sounds, shows increased data usage, or constantly crashes and stops working, it could be infected. 
• Strange apps, new default browser homepages, and invasive ads. Many malware infections continue to target you in different ways. Beware of unfamiliar apps on your phone, especially if you didn’t download them from the Google Play Store or Apple App Store — and changes to your web browser, such as a new default homepage, search engine, or extensions — as well as invasive pop-up ads or scareware notifications, such as fake virus alerts from Microsoft or Windows 10. 
• Ransomware or blackmail messages. Consider any message from someone threatening to delete or leak your personal files and private data a clear sign of a virus. However, beware of fake blackmail messages meant to scare you into paying hackers. 
• You’re locked out of your online accounts. Hackers use malware to access and take over your online accounts (email, online banking, social media, Apple ID, etc.). If you can’t access your online accounts by using your usual passwords, you may have been hacked.
• Your contacts receive unusual messages from you. Some malware uses your messaging and email accounts to send phishing messages and other scams to your contacts. If you hear from friends and family members that they received spam or odd links sent from your accounts, your device could be affected. 
• Warnings that your personal information has been leaked. Once hackers infect your device, they often leak your personal data on the Dark Web. If you receive a notification that your data has been leaked, it could be due to a virus. Even without a notification, an uptick in scam attempts could mean that hackers have your phone number or other sensitive personal information.

Pro tip: While phone viruses pose a real threat, hackers are much more likely to target your online accounts. For the best protection, consider an all-in-one digital security solution that protects against viruses, hacking, fraud, scams, and more. 

What a Factory Reset Can and Cannot Do To Protect Your Phone

A factory reset returns your device to its original state. Since this effectively reinstalls the operating system (OS) and erases your personal files and customizations from the hard drive, the factory reset option should only be used as a last resort to remove viruses (and if you have a recent, clean backup that you can use to restore your device’s data). 

Still, a factory reset can be an effective strategy to use against many types of malware. However, it may not cure everything. For example, performing a factory reset can't remove hackers from your online accounts or destroy malware that has attached itself deeply in your device’s hardware or system files.

The bottom line: Digital security is about more than just protecting your phone against viruses. Aura’s award-winning, all-in-one digital safety solution monitors and protects your devices, personal data, identity, finances, and more. Try Aura for free today.

How To Factory Reset Your Android Device

The exact factory reset process for Android devices depends on the phone manufacturer. 

Before following the general steps below, be sure to back up your data — as these steps will delete all of your files and settings. 

1. Visit your phone or mobile device’s Settings app.
2. Click on General Management. 
3. Select Reset, and then click on Factory Data Reset. 
4. If you can’t access your settings app, an alternate factory reset option is to hold down the power and volume buttons on your device [*].

Pro tip: Each Android device is slightly different. Visit your phone manufacturer’s support page to learn more about how to perform a factory reset on your specific device.

How To Factory Reset Your iPhone or iPad

Before you factory reset your iOS device, make sure your data has been backed up, as this will remove all data and settings. 

Once you’re ready, you can use one of the following methods to factory reset your iPhone or other iOS device:

1. Factory reset via Settings. Click on Settings in your iPhone, then General, and then Reset iPhone. Finally, click on Erase All Content and Settings. 
2. Factory reset via MacOS Finder. Connect your phone to a computer running MacOS 10.15 (or later) and open the Finder. Click on the iPhone icon, then General, and then Restore iPhone.
3. Factory Reset via iTunes. Connect your phone to a computer and launch iTunes. Click on the iPhone icon at the top, then Summary, and then Restore iPhone. 

💡 Related: Can Macs Get Viruses? How To Remove Malware From Macs →

How To Completely Remove Viruses From Your Phone

1. Power down and restart your phone
2. Scan your device with mobile antivirus software
3. Delete suspicious apps
4. Clear your cache and browsing history
5. Make sure you’re not out of device memory or storage space
6. Update to the latest version of your phone’s OS
7. Boot the device in safe mode
8. Restore your phone to a secure backup
9. Update your account passwords and enable 2FA

A factory reset isn’t always the right or best option for a phone that is showing signs of being hacked or infected. Before completely wiping your device, try these troubleshooting steps for removing viruses.

1. Power down and restart your phone

Many virus warning signs resemble standard poor performance issues in a device. By restarting your phone, your device clears its random access memory (RAM), shuts down any processes or apps running in the background, and fixes temporary software and app glitches. 

How to restart your phone:

• How to restart an Android device. Depending on your device, you can restart your phone by holding down the power button or by holding down the power button and one of the volume buttons at the same time. You can then click on Restart. 
• How to restart an iPhone or other iOS device. Depending on your iPhone version, you can restart the device by holding the power button or holding the side button and either volume button. You can then slide the power-off slider that appears. 

2. Scan your device with mobile antivirus software

Antivirus software has the power to detect, quarantine, and remove malicious programs from most Android phones. However, while you may find antivirus software for your iPhone in the App store, it won’t actually scan your device for viruses (as Apple doesn’t allow apps to have this level of access to your device). Instead, you’re more likely to find a digital security app that helps protect your online accounts and identity.

How to run an antivirus scan on your Android:

• Download Aura or another trusted antivirus app from the Google Play Store. 
• Run a “full scan” to detect, quarantine, and remove malicious files and software. 
• Use Google Play protect by clicking on your profile in Google Play and then selecting Play Protect and then Scan.

📚 Learn more: How to Check For Viruses on an iPhone →

3. Delete suspicious apps

Unsafe or unfamiliar apps can house viruses, cause your device to run poorly, or give hackers access to your system settings, files, and more. Removing old, outdated, or unknown apps from your phone can keep you safe — and keep your device running smoothly.

How to delete apps:

• How to delete apps on Android. Open the Google Play Store and click on your profile. In the Manage apps & devices section, click on the app you want to delete and then click on Uninstall.
• How to delete apps on iPhone. Touch and hold the app you wish to delete and click on Delete App. You can also find the app in your App Library and click on Delete App. 

4. Clear your cache and browsing history

Your cache contains temporary files and scripts from websites and apps to help them load faster. While this can help your device operate properly, a full cache can cause poor performance or even give viruses a place to hide. 

How to clear your browser’s cache and history:

• How to clear cache and history on Chrome. Open the Chrome drop-down menu by clicking on the three dots at the top right of the screen. Click on History and then Clear browsing data. Check the boxes for Cookies and site data and Cached images and files, too.
• How to clear cache and history on Safari. Open Safari settings and click on Clear History and Website Data.

📚 Related: How To Get Rid Of the Apple Security Alert and Mac Pop-up Scams →

5. Make sure you’re not out of device memory or storage space

When your device’s memory or storage space gets depleted, you could encounter sluggish performance, crashes, and data loss. 

How to check your device memory:

• How to check Android memory. Open your Files app to review your Internal storage. You can also click on Analyze storage for optimization suggestions. 
• How to check iPhone memory. Click on Settings, then General, and then your iPhone Storage. Here you'll find a list of your apps along with the amount and type of storage each app uses.

6. Update to the latest version of your phone’s OS

An outdated operating system could have exploitable vulnerabilities and bugs that weaken your security. Updating your OS will provide you with patches, enhanced security features, and better compatibility with your phone's features and apps. 

How to update your phone's OS:

• How to update your OS on Android. In your phone Settings, click on Software update or System and then System update. 
• How to update your OS on iPhone.  In the General section of your iPhone Settings, click on Software Update. Then click on Install or Download and Install on the OS version you want. 

7. Boot the device in safe mode

One way to test if an app or file is causing issues is to launch your phone in “safe mode,” which features limited functionality, apps, and system settings. While booting your device in safe mode won't remove viruses, if your device runs fine in safe mode, you likely have an app issue. 

How to boot your phone in safe mode:

• How to boot an Android device in safe mode. The process varies by phone, but many Androids enter safe mode by first powering down the device and then holding down one of the volume buttons while you power it back on. You can then reboot the device to exit safe mode. 
• How to boot an iPhone in safe mode. iPhones do not have a safe mode. Instead, you can reboot the device and remove any recently added apps to troubleshoot. 

📚 Related: How To Remove Viruses From Your Computer (Mac and PC) →

8. Restore your phone to a secure backup

Backups allow you to save all of your files and settings in case something happens to your device. If you have a backup that was made before the issues started, restoring it to that previous version can remove many viruses or corrupted files and apps.

How to restore your phone to a safe backup:

• How to restore an Android device from a backup. For most Android devices, you will find your backups in the Accounts and backup section of your Settings. You can then click on Restore data. 
• How to restore an iPhone from a backup. If you have a backup on a Mac, connect the iPhone and open the Finder. Select your phone and click on Restore Backup. You can also restore from iCloud, but you need to first erase all content from the device. You can then follow the steps upon restarting the phone. 

9. Update your account passwords and enable 2FA

If your problem lies with your online accounts, updating your passwords and enabling two-factor authentication (2FA) could fix the issue. If there is a virus, it could have come from an exposed online account. Either way, this step is crucial for device security. 

How to update your account passwords:

• How to update Google passwords. Change your Google Account password by clicking on Google in your phone's Settings. From there, click on Manage your Google Account and then Security. You can update your password and activate 2FA here. ‍
• How to update Apple passwords. Change your Apple ID password by clicking on your account name in the Settings page. Then click on Sign-In & Security and Change Password. You can also see all of your saved passwords by clicking on Passwords in your Settings.

How Can a Virus Return After a Factory Reset?

Some viruses are especially resilient and will remain even after you implement a factory reset or follow many of the steps above. 

Here are some of the reasons why a factory reset may not be working for you:

• Your data backup is infected. The most common cause for returning viruses is if you accidentally reinstall infected apps or files during your back up process. Always make sure you’re backing up to a secure backup by scanning it with antivirus software. 
• Your device was infected with a rootkit or bootkit virus. These sophisticated viruses can affect the BIOS or other firmware, which can hide from factory resets and may require reflashing or other advanced steps to remove.  
• The malware has infected your device’s recovery partition. The factory reset function deletes and uninstalls everything except for the items in the recovery partition — which it uses to reboot the system. If malware preserves itself here, it can reinfect your device once it refreshes.  
• Other connected devices are infected. A hard reset only cleans your device. If you reconnect the phone to infected external media, Wi-Fi adapters, or routers, your device could be reinfected. 
• Zero-day or unpatched vulnerabilities. If you encountered a virus from a zero-day or unpatched vulnerability, your device will again be at risk as soon as it boots back up after the factory reset.  

How To Protect Your Phone From Viruses

While viruses pose serious threats to our phones and other devices, they're just one of many online dangers. Cybercriminals can scam you and hack your iPhone and Android devices in any number of ways. For effective protection, you need to practice good cyber hygiene at all times.

Try applying the following tips to keep your phone and accounts safe:

• Set up strong and unique passwords for each of your devices and accounts.
• Use multi-factor authentication (MFA) when available.
• Consider a VPN for your iPhone or Android phone, especially when using public Wi-Fi.
• Stay on top of operating system, browser, and app updates for your devices.
• Only download apps from authorized app stores.
• Scrutinize every email, text, and phone call for signs of a phishing scam.
• Avoid clicking on links or downloading files in unsolicited emails and texts.
• Monitor your online and financial accounts regularly for signs of fraud.

A factory reset can be a powerful tool to clean out viruses from your device, but it isn't always foolproof. Viruses often reflect a symptom of deeper and more serious digital security problems. 

For complete protection, consider Aura's all-in-one digital security solution. With Aura, you get a full suite of advanced digital security tools, award-winning identity theft and fraud protection with the industry’s fastest fraud alerts, 24/7 access to U.S.-based White Glove Fraud Resolution Specialists, and up to $5 million in identity theft insurance for your family. 

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