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Remove Mozilla Firefox Critical ERROR (Removal Guide) - Virus Removal Instructions

removal by Olivia Morelli - - | Type: Malware

Mozilla Firefox Critical ERROR is not legitimate security alert

Screenshot of Mozilla Firefox Critical ERROR

Mozilla Firefox Critical ERROR is a fake message sent by cyber criminals to trick computer user’s that their personal and banking information is at risk. However, it’s a scam that is similar to Microsoft Edge Critical error or Internet Explorer Critical error. The major differences are that scammers target different browser’s users [1]and use different phone number to communicate with victims.

Users are usually redirected to Mozilla Firefox Critical ERROR scam website after adware infiltration or visit the infected site. In the background, it is written that someone tried to get access to personal logins and bank information. Additionally, it warns about the possibility of damaged hard disk data due to the trojan virus attack.

Additionally, Mozilla Firefox Critical ERROR virus delivers a pop-up that requires authentication. People are asked to enter their username and password. Obviously, no one has them. So, they are asked to call a “toll-free” support number. The full message of the fake alert:

http://0x00381136100.bid is requesting your username and password. The site says:
“FIREFOX_CRITICAL_ERROR_0xKB1546764_CALL_HELP_DESK: +1 (877) 556-6888 (Toll-Free)”

However, there are several variations of the Mozilla Firefox Critical ERROR scam which provides other phone numbers and error codes. Another version was reported giving a 0xKB6301092 error and using +1 (877) 777-8951 phone number, but that might not be it.

Keep in mind that calling provided number is not recommended. Fake tech support specialists might try to obtain sensitive information, swindle the money,[2] or sell useless software that might be malicious too. Additionally, they might convince you to install remote access tools and get control over your computer.

If you ended up on a scam website only once, you might not need to take any additional actions. It should be enough to close Firefox and forget about the accident. However, some users report that they were unable to close it. In this case, you should force quit the browser in order to remove Mozilla Firefox Critical ERROR from the screen.

However, if you are frequently redirected to this tech support scam site, you might have adware program installed. You can suspect infiltration of the ad-supported app if you:

  • noticed an increased amount of pop-ups, banners, and other types of online ads;
  • found random text turned into hyperlinks;
  • are continuously redirected to other suspicious websites.

In this case, we highly recommend opting for the automatic Mozilla Firefox Critical ERROR removal. It requires scanning the system with reputable anti-malware software, such as Reimage Reimage Cleaner Intego.

Image of Mozilla Firefox Critical ERROR scamMozilla Firefox Critical ERROR is a fake alert that is designed to trick Firefox users that their private information is in danger.

Reason to be careful with freeware and shareware downloads

Mozilla Firefox Critical ERROR adware, as well as many other potentially unwanted programs (PUPs), often spread bundled with free programs, including freeware and shareware. Incorrect installation of a new application might lead to the hijacked web browser. Thus, you might suffer from redirects, aggressive ads, and other suspicious activities.

For this reason, users should attentively and correctly install programs in order to make sure that they do not let any suspicious components get inside the system as well. A security team from DieViren[3] suggests following these tips:

  • Use official software download sites instead of unauthorized and unknown services;
  • Read EULA, Terms of Use, Privacy Policy and other provided information by developers;
  • Use Advanced/Custom settings rather than Quick/Recommended;
  • Opt out pre-selected apps that are offered to download along with the program you need.

Get rid of “Mozilla Firefox Critical ERROR” pop-ups

To stop redirects to suspicious websites, you have to remove Mozilla Firefox Critical ERROR adware from the computer. You can follow the manual guide below and try to locate adware-related components manually. However, it might be challenging, and unwanted browsing activities might continue.

To succeed, we recommend going for automatic Mozilla Firefox Critical ERROR removal. After the system scan with an updated anti-malware software, you will need to reset Mozilla Firefox and continue browsing the web without any problems.

You may remove virus damage with a help of Reimage Reimage Cleaner Intego. SpyHunter 5Combo Cleaner and Malwarebytes are recommended to detect potentially unwanted programs and viruses with all their files and registry entries that are related to them.

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What to do if failed?
If you failed to remove virus damage using Reimage Intego, submit a question to our support team and provide as much details as possible.
Reimage Intego has a free limited scanner. Reimage Intego offers more through scan when you purchase its full version. When free scanner detects issues, you can fix them using free manual repairs or you can decide to purchase the full version in order to fix them automatically.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Reimage, try running SpyHunter 5.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Intego, try running Combo Cleaner.

To remove Mozilla Firefox Critical ERROR, follow these steps:

Uninstall Mozilla Firefox Critical ERROR from Windows systems

In order to remove adware that is responsible for Mozilla Firefox Critical ERROR technical support scam, you have to investigate the system by following these steps:

To remove Mozilla Firefox Critical ERROR from Windows 10/8  machines, please follow these steps:

  1. Enter Control Panel into Windows search box and hit Enter or click on the search result.
  2. Under Programs, select Uninstall a program.Uninstall from Windows 1
  3. From the list, find entries related to Mozilla Firefox Critical ERROR (or any other recently installed suspicious program).
  4. Right-click on the application and select Uninstall.
  5. If User Account Control shows up, click Yes.
  6. Wait till uninstallation process is complete and click OK.Uninstall from Windows 2

If you are Windows 7/XP user, proceed with the following instructions:

  1. Click on Windows Start > Control Panel located on the right pane (if you are Windows XP user, click on Add/Remove Programs).
  2. In Control Panel, select Programs > Uninstall a program.Uninstall from Windows 7/XP
  3. Pick the unwanted application by clicking on it once.
  4. At the top, click Uninstall/Change.
  5. In the confirmation prompt, pick Yes.
  6. Click OK once the removal process is finished.

Get rid of Mozilla Firefox Critical ERROR from Mac OS X system

Follow these steps to remove PUP from Mac OS X:

If your macOS is displaying some infection symptoms, proceed with the following guide:

Remove Mozilla Firefox Critical ERROR from Applications folder:

  1. From the menu bar, select Go > Applications.
  2. In the Applications folder, look for Mozilla Firefox Critical ERROR-related entries.
  3. Click on the app and drag it to Trash (or right-click and pick Move to Trash)Uninstall from Mac 1

To fully remove Mozilla Firefox Critical ERROR, you need to access Application Support, LaunchAgents, and LaunchDaemons folders and delete relevant files:

  1. Select Go > Go to Folder.
  2. Enter /Library/Application Support and click Go or press Enter.
  3. In the Application Support folder, look for any dubious entries related to Mozilla Firefox Critical ERROR and then delete them.
  4. Now enter /Library/LaunchAgents and /Library/LaunchDaemons folders the same way and terminate all the Mozilla Firefox Critical ERROR-related entries.Uninstall from Mac 2

Remove Mozilla Firefox Critical ERROR from Internet Explorer (IE)

Remove dangerous add-ons:

  1. Open Internet Explorer, click on the Gear icon (IE menu) on the top-right corner of the browser
  2. Pick Manage Add-ons.
  3. You will see a Manage Add-ons window. Here, look for Mozilla Firefox Critical ERROR and other suspicious plugins. Click on these entries and select Disable.Remove add-ons from Internet Explorer

Change your homepage if it was altered:

  1. Open IE and click on the Gear icon.
  2. Select Internet Options.
  3. In the General tab, delete the Home page address and replace it by your preferred one (for example, Google.com).
  4. Click Apply and then select OK.Reset IE homepage

Delete temporary files:

  1. Press on the Gear icon and select Internet Options.
  2. Under Browsing history, click Delete…
  3. Select relevant fields and press Delete.Clear temporary files from Internet Explorer

Reset Internet Explorer:

  1. Click on Gear icon > Internet options and select Advanced tab.
  2. Select Reset.
  3. In the new window, check Delete personal settings and select Reset again to complete Mozilla Firefox Critical ERROR removal.Reset Internet Explorer

Delete Mozilla Firefox Critical ERROR from Microsoft Edge

Delete unwanted extensions from MS Edge:

  1. Select Menu (three horizontal dots at the top-right of the browser window) and pick Extensions.
  2. From the list, pick the Mozilla Firefox Critical ERROR-related extension and click on the Gear icon.
  3. Click on Uninstall at the bottom.Remove extensions from Edge

Clear cookies and other browser data:

  1. Click on the Menu (three horizontal dots at the top-right of the browser window) and select Privacy & security.
  2. Under Clear browsing data, pick Choose what to clear.
  3. Select everything (apart from passwords, although you might want to include Media licenses as well, if applicable) and click on Clear.Clear Edge browsing data

Reset MS Edge if that above steps did not work:

  1. Press on Ctrl + Shift + Esc to open Task Manager.
  2. Click on More details arrow at the bottom of the window.
  3. Select Details tab.
  4. Now scroll down and locate every entry with Microsoft Edge name in it. Right-click on each of them and select End Task to stop MS Edge from running.Reset MS Edge

If this solution failed to help you, you need to use an advanced Edge reset method. Note that you need to backup your data before proceeding.

  1. Find the following folder on your computer: C:\\Users\\%username%\\AppData\\Local\\Packages\\Microsoft.MicrosoftEdge_8wekyb3d8bbwe.
  2. Press Ctrl + A on your keyboard to select all folders.
  3. Right-click on them and pick DeleteAdvanced MS Edge reset 1
  4. Now right-click on the Start button and pick Windows PowerShell (Admin).
  5. When the new window opens, copy and paste the following command, and then press Enter:

    Get-AppXPackage -AllUsers -Name Microsoft.MicrosoftEdge | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register “$($_.InstallLocation)\\AppXManifest.xml” -VerboseAdvanced MS Edge reset 2

Instructions for Chromium-based Edge

Delete extensions from MS Edge (Chromium):

  1. Open Edge and click select Settings > Extensions.
  2. Delete unwanted extensions by clicking Remove.Remove extensions from Chromium Edge

Clear cache and site data:

  1. Click on Menu and go to Settings.
  2. Select Privacy and services.
  3. Under Clear browsing data, pick Choose what to clear.
  4. Under Time range, pick All time.
  5. Select Clear now.Clear browser data from Chroum Edge

Reset Chromium-based MS Edge:

  1. Click on Menu and select Settings.
  2. On the left side, pick Reset settings.
  3. Select Restore settings to their default values.
  4. Confirm with Reset.Reset Chromium Edge

Erase Mozilla Firefox Critical ERROR from Mozilla Firefox (FF)

To stop redirects and Mozilla Firefox Critical ERROR ads, you have to uninstall questionable add-ons and reset Mozilla Firefox as shown below:

Remove dangerous extensions:

  1. Open Mozilla Firefox browser and click on the Menu (three horizontal lines at the top-right of the window).
  2. Select Add-ons.
  3. In here, select plugins that are related to Mozilla Firefox Critical ERROR and click Remove.Remove extensions from Firefox

Clear cookies and site data:

  1. Click Menu and pick Options.
  2. Go to Privacy & Security section.
  3. Scroll down to locate Cookies and Site Data.
  4. Click on Clear Data…
  5. Select Cookies and Site Data, as well as Cached Web Content and press Clear.Clear cookies and site data from Firefox

In case Mozilla Firefox Critical ERROR did not get removed after following the instructions above, reset Mozilla Firefox:

  1. Open Mozilla Firefox browser and click the Menu.
  2. Go to Help and then choose Troubleshooting Information.Reset Firefox 1
  3. Under Give Firefox a tune up section, click on Refresh Firefox…
  4. Once the pop-up shows up, confirm the action by pressing on Refresh Firefox – this should complete Mozilla Firefox Critical ERROR removal.Reset Firefox 2

Eliminate Mozilla Firefox Critical ERROR from Google Chrome

Delete malicious extensions from Google Chrome:

  1. Open Google Chrome, click on the Menu (three vertical dots at the top-right corner) and select More tools > Extensions.
  2. In the newly opened window, you will see all the installed extensions. Uninstall all the suspicious plugins that might be related to Mozilla Firefox Critical ERROR by clicking Remove.Remove extensions from Chrome

Clear cache and web data from Chrome:

  1. Click on Menu and pick Settings.
  2. Under Privacy and security, select Clear browsing data.
  3. Select Browsing history, Cookies and other site data, as well as Cached images and files.
  4. Click Clear data.Clear cache and web data from Chrome

If the above-methods did not help you, reset Google Chrome to eliminate all the Mozilla Firefox Critical ERROR-components:

  1. Click on Menu and select Settings.
  2. In the Settings, scroll down and click Advanced.
  3. Scroll down and locate Reset and clean up section.
  4. Now click Restore settings to their original defaults.
  5. Confirm with Reset settings to complete Mozilla Firefox Critical ERROR removal.Reset Chrome 2

Uninstall Mozilla Firefox Critical ERROR from Safari

Remove unwanted extensions from Safari:

  1. Click Safari > Preferences…
  2. In the new window, pick Extensions.
  3. Select the unwanted extension related to Mozilla Firefox Critical ERROR and select Uninstall.Remove extensions from Safari

Clear cookies and other website data from Safari:

  1. Click Safari > Clear History…
  2. From the drop-down menu under Clear, pick all history.
  3. Confirm with Clear History.Clear cookies and website data from Safari

Reset Safari if the above-mentioned steps did not help you:

  1. Click Safari > Preferences…
  2. Go to Advanced tab.
  3. Tick the Show Develop menu in menu bar.
  4. From the menu bar, click Develop, and then select Empty Caches.Reset Safari

Do not let government spy on you

The government has many issues in regards to tracking users' data and spying on citizens, so you should take this into consideration and learn more about shady information gathering practices. Avoid any unwanted government tracking or spying by going totally anonymous on the internet. 

You can choose a different location when you go online and access any material you want without particular content restrictions. You can easily enjoy internet connection without any risks of being hacked by using Private Internet Access VPN.

Control the information that can be accessed by government any other unwanted party and surf online without being spied on. Even if you are not involved in illegal activities or trust your selection of services, platforms, be suspicious for your own security and take precautionary measures by using the VPN service.

Backup files for the later use, in case of the malware attack

Computer users can suffer from data losses due to cyber infections or their own faulty doings. Ransomware can encrypt and hold files hostage, while unforeseen power cuts might cause a loss of important documents. If you have proper up-to-date backups, you can easily recover after such an incident and get back to work. It is also equally important to update backups on a regular basis so that the newest information remains intact – you can set this process to be performed automatically.

When you have the previous version of every important document or project you can avoid frustration and breakdowns. It comes in handy when malware strikes out of nowhere. Use Data Recovery Pro for the data restoration process.

About the author
Olivia Morelli
Olivia Morelli - Ransomware analyst

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