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Critical Firefox Update virus. How to remove? (Uninstall guide)

removal by Gabriel E. Hall - - | Type: Malware
12

Fake Critical Firefox Update spreads Kovter Trojan

Screenshot of fake Critical Firefox Update

Critical Firefox Update is a malicious pop-up which is most likely to pop-up on the screen when users visit adult-themed websites. The fake update alert is delivered by the compromised Traffic Junky ads that distribute the hazardous Kovter.C Trojan.

The Critical Firefox Update virus is one of the components of the huge malvertising campaign created by KovCoreG group. Criminals compromised a Traffic Junky ad-network which places ads on the Pornhub website. According to the Proofpoint research,[1] the campaign may have been active for a year. Fortunately, it was stopped.

The whole malvertising campaign targeted Firefox, Chrome, Explorer, and Microsoft Edge web browsers. While Mozilla Firefox users received the Critical Firefox Update pop-up, Chrome users were targeted by Critical Chrome Update. Meanwhile, Windows browser’s users received fake Adobe Flash Player’s update.[2]

Millions of computer users in the United Kingdom,[3] the United States, Canada, and Australia suffered from this cyber attack. Victims were redirected to a fake update website as soon they visited the adult-themed website.

The fake Firefox update website included an active download button that dropped firefox-patch.js file which has nothing in common with updating the browser. This javascript file belongs to the Kovter trojan and executes it on the system.

This Critical Firefox Update virus might also inject malicious code into various Windows OS processes, alter Registry and execute PowerShell commands. The malicious program might also let cyber criminal to launch click-fraud activities or install other malicious programs on the device.

Even though this malvertising campaign is stopped, users are advised to stay vigilant and avoid downloading fake updates. However, if you suspect that you may have installed this malicious Firefox update, you have to run a full system scan with Reimage or another security software to remove Critical Firefox Update malware.

Additionally automatic Critical Firefox Update removal is necessary to wipe out all malicious components from the system, including the Kovter.C trojan which might be responsible for stealing sensitive information or installing other malware on the device.

Be careful with drive-by downloads

Critical Firefox Update malware spreads in the form of a pop-up that pretends to be a legit browser’s update. The Kovter trojan is installed on the system as soon as a person clicks “Download” button and lets the malicious Javascript file is downloaded. Therefore, users are advised to be careful with update alerts. Before agreeing to install any content from the web, you have to make sure that it’s actually safe.

Even though this malvertising campaign is stopped, similar cyber threats are still lurking on the web. While browsing the internet, you might notice Urgent Firefox Update ads or similar alerts which might also be capable of spreading malicious programs.

Keep in mind that legit software updates do not pop up in the browser’s new tab. Usually, they arrive in the form of a program window. However, you have always to check available updates on the publisher’s website to avoid fatal mistakes.

Terminate Critical Firefox Update virus and Kovter trojan

If you have downloaded a malicious file, you have to run a full system scan with a reputable anti-malware software to remove Critical Firefox Update virus and Kovter malware from the device. We highly recommend scanning the system with Reimage or Malwarebytes Anti Malware. However, you can choose your preferred security tool as well.

It’s important to complete this task immediately because the trojan might steal sensitive and banking-related information. If you cannot perform automatic Critical Firefox Update removal, please follow the instructions below. They will show you how to disable the virus first.

 

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What to do if failed?
If you failed to remove infection using Reimage, submit a question to our support team and provide as much details as possible.
Reimage is recommended to uninstall Critical Firefox Update virus. Free scanner allows you to check whether your PC is infected or not. If you need to remove malware, you have to purchase the licensed version of Reimage malware removal tool.

More information about this program can be found in Reimage review.

More information about this program can be found in Reimage review.

Manual Critical Firefox Update virus Removal Guide:

Remove Critical Firefox Update using Safe Mode with Networking

Reimage is a tool to detect malware.
You need to purchase Full version to remove infections.
More information about Reimage.

Follow these steps to disable malware and run automatic removal:

  • Step 1: Reboot your computer to Safe Mode with Networking

    Windows 7 / Vista / XP
    1. Click Start Shutdown Restart OK.
    2. When your computer becomes active, start pressing F8 multiple times until you see the Advanced Boot Options window.
    3. Select Safe Mode with Networking from the list Select 'Safe Mode with Networking'

    Windows 10 / Windows 8
    1. Press the Power button at the Windows login screen. Now press and hold Shift, which is on your keyboard, and click Restart..
    2. Now select Troubleshoot Advanced options Startup Settings and finally press Restart.
    3. Once your computer becomes active, select Enable Safe Mode with Networking in Startup Settings window. Select 'Enable Safe Mode with Networking'
  • Step 2: Remove Critical Firefox Update

    Log in to your infected account and start the browser. Download Reimage or other legitimate anti-spyware program. Update it before a full system scan and remove malicious files that belong to your ransomware and complete Critical Firefox Update removal.

If your ransomware is blocking Safe Mode with Networking, try further method.

Remove Critical Firefox Update using System Restore

Reimage is a tool to detect malware.
You need to purchase Full version to remove infections.
More information about Reimage.

This method might also help to run security software and remove Critical Firefox Update virus as well as Kovter trojan:

  • Step 1: Reboot your computer to Safe Mode with Command Prompt

    Windows 7 / Vista / XP
    1. Click Start Shutdown Restart OK.
    2. When your computer becomes active, start pressing F8 multiple times until you see the Advanced Boot Options window.
    3. Select Command Prompt from the list Select 'Safe Mode with Command Prompt'

    Windows 10 / Windows 8
    1. Press the Power button at the Windows login screen. Now press and hold Shift, which is on your keyboard, and click Restart..
    2. Now select Troubleshoot Advanced options Startup Settings and finally press Restart.
    3. Once your computer becomes active, select Enable Safe Mode with Command Prompt in Startup Settings window. Select 'Enable Safe Mode with Command Prompt'
  • Step 2: Restore your system files and settings
    1. Once the Command Prompt window shows up, enter cd restore and click Enter. Enter 'cd restore' without quotes and press 'Enter'
    2. Now type rstrui.exe and press Enter again.. Enter 'rstrui.exe' without quotes and press 'Enter'
    3. When a new window shows up, click Next and select your restore point that is prior the infiltration of Critical Firefox Update. After doing that, click Next. When 'System Restore' window shows up, select 'Next' Select your restore point and click 'Next'
    4. Now click Yes to start system restore. Click 'Yes' and start system restore
    Once you restore your system to a previous date, download and scan your computer with Reimage and make sure that Critical Firefox Update removal is performed successfully.

Finally, you should always think about the protection of crypto-ransomwares. In order to protect your computer from Critical Firefox Update and other ransomwares, use a reputable anti-spyware, such as Reimage, Plumbytes Anti-MalwareWebroot SecureAnywhere AntiVirus or Malwarebytes Anti Malware

About the author

Gabriel E. Hall
Gabriel E. Hall - Passionate web researcher

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References