The Critical Security Warning is classified as misleading ‘ad’ web page. This web page is designed to force you into calling the fake Support Service or installing an questionable software. This misleading page can display fake pop up alerts and warnings or redirect your browser to other malicious and misleading sites. If the Chrome, Safari, Internet Explorer, Firefox or Microsoft Edge browser opens automatically to “Critical Security Warning” then it is a sign that your computer has been hijacked with the nasty adware (also known as ‘ad-supported’ software). As a result of the adware infection, your web-browser will be full of advertisements (pop-ups, banners, in-text links, offers to install an undesired apps) and your PC system will be slower and slower.
“Critical Security Warning” is a misleading advertising
Technically, the adware that opens the “Critical Security Warning” fake alerts, is not a virus, but it does bad things, it generates tons of ads. It may download and install on to your computer other harmful and undesired applications without your permission, force you to visit misleading or malicious web-sites. Moreover, the adware can install browser hijacker. Once installed, it will replace your web-browser setting like home page, newtab and search provider by default with an intrusive page.
The malicious software from the adware family that modifies the settings of internet browsers usually affects only the Google Chrome, Mozilla Firefox, Edge and Internet Explorer. However, possible situations, when any other web browsers will be infected too. The ‘ad supported’ software may change the Target property of a web-browser’s shortcut file, so every time you run the web browser, instead of your start page, you will see the annoying “Critical Security Warning” web-site.
We recommend to remove the adware which cause misleading “Critical Security Warning” pop up scam to appear, as soon as you found this problem, as it can reroute your web browser to web-resources which may load other harmful software on your PC.
Remove “Critical Security Warning” pop-up
There are a few solutions that can be used to remove “Critical Security Warning” popup scam. But, not all potentially unwanted software like this adware can be completely removed using only manual methods. In many cases you are not able to delete any adware utilizing standard Windows options. In order to delete “Critical Security Warning” pop-up you need complete a few manual steps and use reliable removal utilities. Most IT security professionals states that Zemana Free, MalwareBytes Anti Malware (MBAM) or AdwCleaner tools are a right choice. These free programs are able to scan for and get rid of “Critical Security Warning” pop-up scam from your PC and revert back your web browser settings to defaults.
To remove “Critical Security Warning” pop-up, complete the following steps:
- Manual “Critical Security Warning” pop up scam removal
- Removing the “Critical Security Warning”, check the list of installed software first
- Remove unwanted Scheduled Tasks
- Get rid of “Critical Security Warning” from Firefox by resetting internet browser settings
- Get rid of “Critical Security Warning” pop up scam from IE
- Remove “Critical Security Warning” popup scam from Google Chrome
- Clean up the internet browsers shortcuts which have been infected by ad supported software
- Run free malware removal tools to completely delete “Critical Security Warning” pop up scam
- Use AdBlocker to block “Critical Security Warning” and stay safe online
- How did “Critical Security Warning” fake alerts get on your machine
- Finish words
Manual “Critical Security Warning” pop up scam removal
Read this “How to remove” section to know how to manually remove adware that causes internet browsers to display misleading “Critical Security Warning” fake alerts. Even if the steps does not work for you, there are several free malicious software removers below that can easily handle such ad supported software that displays misleading “Critical Security Warning” fake alerts on your machine.
Removing the “Critical Security Warning”, check the list of installed software first
The best way to start the computer cleanup is to delete unknown and suspicious programs. Using the Windows Control Panel you can do this quickly and easily. This step, in spite of its simplicity, should not be ignored, because the removing of unneeded programs can clean up the Google Chrome, Firefox, IE and Edge from popups, hijackers and so on.
Windows 8, 8.1, 10
First, click Windows button
, then click Search 
. Type ‘Control panel’and press Enter as shown on the image below.
When the ‘Control Panel’ opens, press the ‘Uninstall a program’ link under Programs category as shown below.
You will see the ‘Uninstall a program’ panel as shown below.
Very carefully look around the entire list of applications installed on your computer. Most probably, one of them is the adware that causes internet browsers to show misleading “Critical Security Warning” pop-up warnings. If you have many applications installed, you can help simplify the search of malicious apps by sort the list by date of installation. Once you have found a dubious, unwanted or unused application, right click to it, after that press ‘Uninstall’.
Windows XP, Vista, 7
First, click ‘Start’ button and select ‘Control Panel’ at right panel as on the image below.
When the Windows ‘Control Panel’ opens, you need to click ‘Uninstall a program’ under ‘Programs’ as on the image below.
You will see a list of programs installed on your machine. We recommend to sort the list by date of installation to quickly find the apps that were installed last. Most likely, it is the ‘ad supported’ software which displays misleading “Critical Security Warning” fake alerts on your computer. If you are in doubt, you can always check the program by doing a search for her name in Google, Yahoo or Bing. After the application which you need to delete is found, simply click on its name, and then click ‘Uninstall’ like below.
Remove unwanted Scheduled Tasks
If the annoying “Critical Security Warning” web site opens automatically on Windows startup or at equal time intervals, then you need to check the Task Scheduler Library and get rid of all the tasks which have been created by adware.
Press Windows and R keys on the keyboard together. This displays a dialog box that titled as Run. In the text field, type “taskschd.msc” (without the quotes) and click OK. Task Scheduler window opens. In the left-hand side, click “Task Scheduler Library”, as displayed in the following example.
Task scheduler
In the middle part you will see a list of installed tasks. Please choose the first task, its properties will be open just below automatically. Next, click the Actions tab. Pay attention to that it launches on your PC system. Found something like “explorer.exe http://site.address” or “chrome.exe http://site.address”, then remove this malicious task. If you are not sure that executes the task, check it through a search engine. If it’s a component of the ‘ad-supported’ program, then this task also should be removed.
Having defined the task that you want to delete, then press on it with the right mouse button and choose Delete as shown below.
Delete a task
Repeat this step, if you have found a few tasks that have been created by ‘ad-supported’ applications. Once is complete, close the Task Scheduler window.
Get rid of “Critical Security Warning” from Firefox by resetting internet browser settings
The Firefox reset will keep your personal information such as bookmarks, passwords, web form auto-fill data, restore preferences and security settings, delete redirections to unwanted “Critical Security Warning” site and ad supported software.
Click the Menu button (looks like three horizontal lines), and click the blue Help icon located at the bottom of the drop down menu as shown below.
A small menu will appear, click the “Troubleshooting Information”. On this page, click “Refresh Firefox” button as displayed in the figure below.
Follow the onscreen procedure to restore your Firefox browser settings to its original state.
Get rid of “Critical Security Warning” pop up scam from IE
In order to restore all browser homepage, new tab and default search engine you need to reset the Microsoft Internet Explorer to the state, that was when the Windows was installed on your machine.
First, start the Internet Explorer. Next, click the button in the form of gear (
). It will open the Tools drop-down menu, press the “Internet Options” as displayed on the screen below.
In the “Internet Options” window click on the Advanced tab, then click the Reset button. The Microsoft Internet Explorer will show the “Reset Internet Explorer settings” window as displayed in the figure below. Select the “Delete personal settings” check box, then click “Reset” button.
You will now need to reboot your machine for the changes to take effect.
Remove “Critical Security Warning” popup scam from Google Chrome
Run the Reset browser utility of the Google Chrome to reset all its settings like home page, newtab page and search provider by default to original defaults. This is a very useful tool to use, in the case of web browser redirects to intrusive ad pages such as “Critical Security Warning”.
Open the Chrome menu by clicking on the button in the form of three horizontal dotes (
). It will display the drop-down menu. Choose More Tools, then click Extensions.
Carefully browse through the list of installed extensions. If the list has the extension labeled with “Installed by enterprise policy” or “Installed by your administrator”, then complete the following tutorial: Remove Google Chrome extensions installed by enterprise policy otherwise, just go to the step below.
Open the Google Chrome main menu again, click to “Settings” option.
Scroll down to the bottom of the page and click on the “Advanced” link. Now scroll down until the Reset settings section is visible, as displayed in the figure below and click the “Reset settings to their original defaults” button.
Confirm your action, press the “Reset” button.
Clean up the internet browsers shortcuts which have been infected by ad supported software
The adware which causes misleading “Critical Security Warning” pop up warnings on your web-browser, may hijack various Windows shortcuts on your desktop (most often, all web-browsers shortcuts), so in this step you need to check and clean them by removing the argument like http://site.address/.
Right click on the shortcut of hijacked web browser as displayed in the following example.
Select the “Properties” option and it’ll show the shortcut’s properties. Next, press the “Shortcut” tab and then delete the “http://site.address” string from Target field like below.
Then click OK to save changes. Repeat the step for all web-browsers which are redirected to the “Critical Security Warning” undesired web site.
Run free malware removal tools to completely delete “Critical Security Warning” pop up scam
The easiest method to delete “Critical Security Warning” fake alerts is to use an anti malware application capable of detecting this ‘ad supported’ software that causes web browsers to display misleading “Critical Security Warning” pop-up warnings. We advise try Zemana Anti-malware or another free malware remover that listed below. It has excellent detection rate when it comes to ad supported software, hijacker infections and other potentially unwanted applications.
Scan and free your web browser of “Critical Security Warning” pop-up with Zemana Anti-malware
We suggest using the Zemana Anti-malware. You can download and install Zemana Anti-malware to find out and delete “Critical Security Warning” pop-up from the Chrome, Firefox, Edge and Microsoft Internet Explorer browsers. When installed and updated, the malware remover will automatically scan and detect all threats present on your PC system.
Download Zemana Free from the following link. Save it on your Desktop.
164032 downloads
Author: Zemana Ltd
Category: Security tools
Update: July 16, 2019
After the downloading process is done, close all windows on your PC. Further, open the install file called Zemana.AntiMalware.Setup. If the “User Account Control” dialog box pops up as shown on the image below, click the “Yes” button.
It will show the “Setup wizard” which will allow you install Zemana Anti Malware on the PC system. Follow the prompts and do not make any changes to default settings.
Once installation is done successfully, Zemana Free will automatically start and you can see its main window as shown in the following example.
Next, click the “Scan” button .Zemana Free application will scan through the whole system for the adware that shows misleading “Critical Security Warning” pop up on your computer. This task can take quite a while, so please be patient. While the Zemana program is scanning, you may see count of objects it has identified as threat.
After finished, the results are displayed in the scan report. Review the results once the tool has finished the system scan. If you think an entry should not be quarantined, then uncheck it. Otherwise, simply click “Next” button.
The Zemana Anti Malware will remove adware which displays misleading “Critical Security Warning” popup warnings on your system and move threats to the program’s quarantine. After the clean-up is done, you can be prompted to reboot your computer.
Automatically remove “Critical Security Warning” fake alerts with Malwarebytes
We advise using the Malwarebytes Free that are completely clean your personal computer of the adware. The free tool is an advanced malicious software removal application created by (c) Malwarebytes lab. This application uses the world’s most popular anti malware technology. It is able to help you delete undesired “Critical Security Warning” fake alerts from your web-browsers, PUPs, malicious software, browser hijackers, toolbars, ransomware and other security threats from your machine for free.
Download MalwareBytes AntiMalware by clicking on the following link. Save it on your Windows desktop or in any other place.
326384 downloads
Author: Malwarebytes
Category: Security tools
Update: April 15, 2020
When the downloading process is complete, close all software and windows on your PC. Open a directory in which you saved it. Double-click on the icon that’s named mb3-setup as shown in the figure below.
When the installation begins, you will see the “Setup wizard” that will help you set up Malwarebytes on your computer.
Once install is done, you will see window like below.
Now click the “Scan Now” button for scanning your computer for the adware that cause misleading “Critical Security Warning” fake alerts to appear. A scan can take anywhere from 10 to 30 minutes, depending on the number of files on your computer and the speed of your system.
After finished, MalwareBytes Free will show you the results. Review the results once the tool has complete the system scan. If you think an entry should not be quarantined, then uncheck it. Otherwise, simply click “Quarantine Selected” button.
The Malwarebytes will now delete adware which designed to display misleading “Critical Security Warning” fake alerts within your web-browser. When finished, you may be prompted to restart your computer.
The following video explains instructions on how to remove browser hijacker, adware and other malware with MalwareBytes Anti Malware (MBAM).
Get rid of “Critical Security Warning” fake alerts from browsers with AdwCleaner
AdwCleaner is a portable utility that finds and removes unwanted apps such as browser hijacker infections, ‘ad supported’ software, toolbars, other web-browser extensions and other malware. It scans your personal computer for adware that causes browsers to show misleading “Critical Security Warning” popup scam and produces a list of threats marked for removal. AdwCleaner will only erase those undesired apps that you wish to be removed.
Click the link below to download the latest version of AdwCleaner for MS Windows. Save it to your Desktop.
225260 downloads
Version: 8.4.1
Author: Xplode, MalwareBytes
Category: Security tools
Update: October 5, 2024
Download and use AdwCleaner on your PC. Once started, click “Scan” button . AdwCleaner tool will begin scanning the whole PC system to find out adware that causes web browsers to show misleading “Critical Security Warning” pop up. This procedure can take quite a while, so please be patient. . When that process is finished, AdwCleaner will display you the results. Once you have selected what you want to remove from your personal computer, click Clean button.
All-in-all, AdwCleaner is a fantastic free utility to free your PC from any unwanted applications. The AdwCleaner is portable program that meaning, you don’t need to install it to run it. AdwCleaner is compatible with all versions of MS Windows OS from Windows XP to Windows 10. Both 64-bit and 32-bit systems are supported.
Use AdBlocker to block “Critical Security Warning” and stay safe online
By installing an ad-blocking program like AdGuard, you are able to stop “Critical Security Warning”, autoplaying video ads and get rid of a lot of distracting and intrusive ads on web-pages.
Download AdGuard program by clicking on the link below. Save it on your Desktop.
26627 downloads
Version: 6.4
Author: © Adguard
Category: Security tools
Update: November 15, 2018
Once downloading is finished, start the downloaded file. You will see the “Setup Wizard” screen as displayed on the screen below.
Follow the prompts. When the installation is finished, you will see a window as displayed in the figure below.
You can press “Skip” to close the installation application and use the default settings, or press “Get Started” button to see an quick tutorial which will allow you get to know AdGuard better.
In most cases, the default settings are enough and you don’t need to change anything. Each time, when you run your personal computer, AdGuard will run automatically and block ads, web sites such “Critical Security Warning”, as well as other malicious or misleading web sites. For an overview of all the features of the application, or to change its settings you can simply double-click on the AdGuard icon, which can be found on your desktop.
How did “Critical Security Warning” fake alerts get on your machine
These days some free applications makers bundle bundled software which could be potentially unwanted software like this ‘ad supported’ software, with a view to making some money. These are not free programs as install an unwanted applications on to your MS Windows computer. So whenever you install a new free program that downloaded from the Internet, be very careful during installation. Carefully read the EULA (a text with I ACCEPT/I DECLINE button), select custom or manual install type, disable all additional applications.
Finish words
After completing the instructions shown above, your system should be free from ad-supported software which causes misleading “Critical Security Warning” fake alerts on your web-browser and other malware. The Google Chrome, IE, FF and Microsoft Edge will no longer reroute you to various unwanted web-pages similar to “Critical Security Warning”. Unfortunately, if the steps does not help you, then you have caught a new adware, and then the best way – ask for help in our Spyware/Malware removal forum.
