Microsoft Detected Malicious Virus And Blocked Your Computer POP-UP Scam

Also Known As: "Microsoft detected malicious virus and blocked your computer" virus
Distribution: Low
Damage level: Medium

"Microsoft detected malicious virus and blocked your computer" removal instructions

What is "Microsoft detected malicious virus and blocked your computer"?

"Microsoft detected malicious virus and blocked your computer" is one of many technical support scams designed to trick people into believing that their systems are infected. Scammers use them to extort money from unsuspecting people by encouraging them to call the telephone number provided. These scams appear on various dubious, untrustworthy websites. People do not generally open them intentionally - often, potentially unwanted apps (PUAs) installed on their systems open these web pages. In addition to unwanted redirects, PUAs usually gather information and serve users with intrusive ads.

Microsoft detected malicious virus and blocked your computer scam

The website that promotes "Microsoft detected malicious virus and blocked your computer" scam is disguised as an "Official Help Care" page. Once opened, it asks people to enter usernames and passwords of their Windows accounts and prevents the dialog window from being closed. We strongly recommend that you do not provide these details. Furthermore, the website itself states that Microsoft has detected malware and blocked the visitor's computer. It encourages them not to restart their computers or to close the opened window. It is stated that the computer registration key is blocked due to one of the following reasons: the key or installed software is illegal; the Windows system is infected and is proliferating viruses over the Internet, or; the operating system is hacked and being used from an undefined location. According to scammers, computers are blocked for safety purposes. To unblock them, they encourage people to call them via the "1-888-879-3955" number. If this page is opened with Mozilla Firefox, it displays an additional pop-up window stating that the detected virus might allow some hackers to steal various information. Since this is a scam, it should not be taken seriously. If contacted, scammers try to sell unnecessary technical services or dubious software. This is to extort money from people and has nothing to do with the Microsoft company. If a browser opens this website, it should be closed. If this cannot be done in the normal way, end the entire browser process using Task Manager. Do not restore the closed browsing session, since this will reopen the deceptive website.

The aforementioned PUAs open various dubious pages, but also gather data and deliver ads. They collect information such as users' IP addresses, geolocations, URLs of visited websites, entered search queries, and so on. Some PUAs might be designed to gather personal details. Their developers share recorded information with other parties (potentially, cyber criminals) who misuse it to generate revenue. Another issue with these apps is intrusive ads. They display various coupons, banners, surveys, pop-ups, and other unwanted advertisements. People who click them are usually redirected to untrustworthy websites (such as this technical support scam) or they allow ads to run scripts designed to download/install unwanted apps.

Threat Summary:
Name "Microsoft detected malicious virus and blocked your computer" virus
Threat Type Phishing, Scam, Social Engineering, Fraud
Fake Claim The fake error claims that the system is infected and has been blocked. It also encourages users to contact Microsoft's 'tech support' via the provided phone number (which is fake).
Tech Support Scammer Phone Number 1-888-879-3955 
Related Website(s) unextinguished[.]site
Serving IP Address (unextinguished[.]site) 45.32.129.194
Symptoms Fake error messages, fake system warnings, pop-up errors, hoax computer scan.
Distribution methods Compromised websites, rogue online pop-up ads, potentially unwanted applications.
Damage Loss of sensitive, private information, monetary loss, identity theft, possible malware infections.
Malware Removal (Windows)

To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Malwarebytes.
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The Internet is full of technical support and other scams, "Enter Windows registration key to unblock", "Error XR01F5" and "Windows protected your PC" are just a few examples. Typically, scammers use them for identical purpose - to extract money from people by encouraging them to pay for unnecessary services or software. These scam websites should never be trusted. Various PUAs should not be used or installed as well. Even if they are promoted as useful and legitimate, most are not. Usually they cause their users various problems relating to privacy, browsing safety and so on. We recommend to uninstall all installed apps of this type immediately.

How did potentially unwanted applications install on my computer?

Unwanted apps are sometimes promoted on supposedly official websites from which they can be downloaded, however, they are mostly downloaded and installed through intrusive advertisements that people click, or during download/installation processes of other software. Developers often use a deceptive marketing method called "bundling" to trick people into causing unwanted downloads/installations through other software setups. They achieve this by hiding PUAs in "Custom", "Advanced" and other similar settings of the setups and hope that people will not check or change them. Leaving them unchanged grants permission for unwanted apps to be downloaded and installed.

How to avoid installation of potentially unwanted applications?

All software should be downloaded from official websites, especially if it is free. Any other sources such as third party downloaders, unofficial, dubious pages, Peer-to-Peer networks and other similar sources cannot be trusted and should not be used. Download and installation processes should be handled properly. It is important to dismiss offers to download or install additional software that is included into the software set-ups. This can be done simply by checking all available "Advanced", "Custom" and other similar settings. Do not to click intrusive advertisements, especially if they are displayed on dubious websites (i.e., pages relating to gambling, adult dating, pornography, and so on). They redirect users to other dubious or even malicious websites. These clicks might also cause unwanted downloads/installations. If a browser causes unwanted redirects or ads are displayed on all visited websites, it is likely that this is caused by an installed PUA. If this is the case, check the list of installed extensions, plug-ins, and add-ons on the browser and remove unwanted, suspicious apps immediately. This also applies to unwanted programs installed on the operating system. If your computer is already infected with PUAs, we recommend running a scan with Malwarebytes for Windows to automatically eliminate them.

Text presented in "Microsoft detected malicious virus and blocked your computer" technical support scam:

The system has been infected with a virus
Attackers might be trying to steal information from your computer. Save your computer by clicking Back to Safety.

Microsoft has detected a malicious virus alert and blocked your computer.
The system has been infected with a virus.
Do not close this window and restart your computer. This computer's registration key is blocked.
Why your system has been blocked?
Illegal window's registration key
This window is sending virus over the Internet.
This window is hacked.
The location is undefined.
Pirated software is used.

We block this computer for your security purpose. Contact Microsoft helpline to reactivate your computer immediately. To unblock your computer, enter security key or call for help. +1-888-879-3955 (Toll Free)

Screenshot of the "Microsoft detected malicious virus and blocked your computer" scam opened with Google Chrome browser:

Microsoft detected malicious virus and blocked your computer opened with chrome browser

Screenshot of the "Microsoft detected malicious virus and blocked your computer" scam opened with Mozilla Firefox browser:

Microsoft detected malicious virus and blocked your computer opened with Mozilla Firefox

Instant automatic malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Malwarebytes is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
▼ DOWNLOAD Malwarebytes By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. To use full-featured product, you have to purchase a license for Malwarebytes. 14 days free trial available.

Quick menu:

Removal of potentially unwanted applications:

Windows 7 users:

Accessing Programs and Features (uninstall) in Windows 7

Click Start (Windows Logo at the bottom left corner of your desktop), choose Control Panel. Locate Programs and click Uninstall a program.

Windows XP users:

Accessing Add or Remove Programs in Windows XP

Click Start, choose Settings and click Control Panel. Locate and click Add or Remove Programs.

Windows 10 and Windows 8 users:

Accessing Programs and Features (uninstall) in Windows 8

Right-click in the lower left corner of the screen, in the Quick Access Menu select Control Panel. In the opened window choose Programs and Features.

Mac OSX users:

Uninstall app in OSX (Mac)

Click Finder, in the opened screen select Applications. Drag the app from the Applications folder to the Trash (located in your Dock), then right click the Trash icon and select Empty Trash.

PUAs uninstall via Control Panel

In the uninstall programs window, look for any suspicious/recently-installed applications, select these entries and click "Uninstall" or "Remove".

After uninstalling the potentially unwanted application, scan your computer for any remaining unwanted components or possible malware infections. To scan your computer, use recommended malware removal software.

Remove rogue extensions from Internet browsers:

Video showing how to remove potentially unwanted browser add-ons:

Internet Explorer logoRemove malicious add-ons from Internet Explorer:

Removing rogue extensions from Internet Explorer step 1

Click the "gear" icon Internet Explorer options icon (at the top right corner of Internet Explorer), select "Manage Add-ons". Look for any recently-installed suspicious browser extensions, select these entries and click "Remove".

Removing rogue extensions from Internet Explorer step 2

Optional method:

If you continue to have problems with removal of the "microsoft detected malicious virus and blocked your computer" virus, reset your Internet Explorer settings to default.

Windows XP users: Click Start, click Run, in the opened window type inetcpl.cpl In the opened window click the Advanced tab, then click Reset.

Resetting Internet Explorer settings to default on Windows XP

Windows Vista and Windows 7 users: Click the Windows logo, in the start search box type inetcpl.cpl and click enter. In the opened window click the Advanced tab, then click Reset.

Resetting Internet Explorer settings to default on Windows 7

Windows 8 users: Open Internet Explorer and click the gear icon. Select Internet Options.

Reseting Internet Explorer settings to default in Windows 8 - accessing

In the opened window, select the Advanced tab.

Resetting Internet Explorer settings to default on Windows 8 - Internet options advanced tab

Click the Reset button.

Resetting Internet Explorer settings to default on Windows 8 - click the Reset button in the Internet options advanced tab

Confirm that you wish to reset Internet Explorer settings to default by clicking the Reset button.

Resetting Internet Explorer settings to default on Windows 8 - confirm settings reset to default by clicking the reset button

Google Chrome logoRemove malicious extensions from Google Chrome:

Removing rogue extensions from Google Chrome step 1

Click the Chrome menu icon Google Chrome menu icon (at the top right corner of Google Chrome), select "More tools" and click "Extensions". Locate all recently-installed suspicious browser add-ons and remove them.

Removing rogue extensions from Google Chrome step 2

Optional method:

If you continue to have problems with removal of the "microsoft detected malicious virus and blocked your computer" virus, reset your Google Chrome browser settings. Click the Chrome menu icon Google Chrome menu icon (at the top right corner of Google Chrome) and select Settings. Scroll down to the bottom of the screen. Click the Advanced… link.

Google Chrome settings reset step 1

After scrolling to the bottom of the screen, click the Reset (Restore settings to their original defaults) button.

Google Chrome settings reset step 2

In the opened window, confirm that you wish to reset Google Chrome settings to default by clicking the Reset button.

Google Chrome settings reset step 3

Mozilla Firefox logoRemove malicious plug-ins from Mozilla Firefox:

Removing rogue extensions from Mozilla Firefox step 1

Click the Firefox menu firefox menu icon (at the top right corner of the main window), select "Add-ons". Click on "Extensions", in the opened window, remove all recently-installed suspicious browser plug-ins.

Removing rogue extensions from Mozilla Firefox step 2

Optional method:

Computer users who have problems with "microsoft detected malicious virus and blocked your computer" virus removal can reset their Mozilla Firefox settings.

Open Mozilla Firefox, at the top right corner of the main window, click the Firefox menu, firefox menu icon in the opened menu, click Help.

Accessing settings (Reset Firefox to default settings step 1)

Select Troubleshooting Information.

Accessing Troubleshooting Information (Reset Firefox to default settings step 2)

In the opened window, click the Refresh Firefox button.

Clicking on Refresh Firefox button (Reset Firefox to default settings step 3)

In the opened window, confirm that you wish to reset Mozilla Firefox settings to default by clicking the Refresh Firefox button.

Confirm your want to reset Firefox settings to default (Reset Firefox to default settings step 4)

safari browser logoRemove malicious extensions from Safari:

removing adware from safari step 1 - accessing preferences

Make sure your Safari browser is active, click Safari menu, and select Preferences....

removing adware from safari step 2 - removing extensions

In the opened window click Extensions, locate any recently installed suspicious extension, select it and click Uninstall.

Optional method:

Make sure your Safari browser is active and click on Safari menu. From the drop down menu select Clear History and Website Data...

resetting safari step 1

In the opened window select all history and click the Clear History button.

resetting safari step 2

Microsoft Edge (Chromium) logoRemove malicious extensions from Microsoft Edge:

Removing adware from Microsoft Edge step 1

Click the Edge menu icon Microsoft Edge (chromium) menu icon (at the upper-right corner of Microsoft Edge), select "Extensions". Locate all recently-installed suspicious browser add-ons and click "Remove" below their names.

Removing adware from Microsoft Edge step 2

Optional method:

If you continue to have problems with removal of the "microsoft detected malicious virus and blocked your computer" virus, reset your Microsoft Edge browser settings. Click the Edge menu icon Microsoft Edge (chromium) menu icon (at the top right corner of Microsoft Edge) and select Settings.

Microsoft Edge (Chromium) reset step 1

In the opened settings menu select Reset settings.

Microsoft Edge (Chromium) reset step 2

Select Restore settings to their default values. In the opened window, confirm that you wish to reset Microsoft Edge settings to default by clicking the Reset button.

Microsoft Edge (Chromium) reset step 3

  • If this did not help, follow these alternative instructions explaining how to reset the Microsoft Edge browser.

Summary:

declining installation of adware while downloading free software sampleCommonly, adware or potentially unwanted applications infiltrate Internet browsers through free software downloads. Note that the safest source for downloading free software is via developers' websites only. To avoid installation of adware, be very attentive when downloading and installing free software. When installing previously-downloaded free programs, choose the custom or advanced installation options – this step will reveal any potentially unwanted applications listed for installation together with your chosen free program.

Removal assistance:
If you are experiencing problems while trying to remove "microsoft detected malicious virus and blocked your computer" virus from your computer, please ask for assistance in our malware support forum.

Post a comment:
If you have additional information on "microsoft detected malicious virus and blocked your computer" virus or it's removal please share your knowledge in the comments section below.

About the author:

Tomas Meskauskas

Tomas Meskauskas - expert security researcher, professional malware analyst.

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for pcrisk.com since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

PCrisk security portal is brought by a company RCS LT. Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.

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Malware activity

Global malware activity level today:

Medium threat activity

Increased attack rate of infections detected within the last 24 hours.

QR Code
Microsoft detected malicious virus and blocked your computer virus QR code
A QR code (Quick Response Code) is a machine-readable code which stores URLs and other information. This code can be read using a camera on a smartphone or a tablet. Scan this QR code to have an easy access removal guide of "Microsoft detected malicious virus and blocked your computer" virus on your mobile device.
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