FacebookTwitterLinkedIn

Remove apps that open "Windows Defender - Security Warning" and similar scams

Also Known As: Windows Defender - Security Warning technical support scam
Damage level: Medium

What is "Windows Defender - Security Warning"?

Generally, scammers behind technical support scams such as this attempt to trick users into believing that their computers are infected, errors exist, etc. They urge users to call the provided number and then pay for unnecessary services and software. In some cases, scammers behind these pages attempt to trick visitors into providing remote access to their computers.

In most cases, users arrive at these sites through other dubious web pages, by clicking deceptive ads, or when installed PUAs open them. In any case, people do not often visit these scam pages intentionally. Note that this site is hosted using the Amazon AWS service provided by Amazon. Scammers and cyber criminals commonly employ this service for malicious purposes.

Windows Defender - Security Warning scam

The pop-up windows, which appear when this technical support website is visited, state that a Trojan, Spyware with error code #0x898778 has been detected and access to the computer has been blocked. Information such as email accounts, Facebook credentials, banking passwords, pictures and documents have also been compromised.

To restore access to the computer, fix the error, and remove detected threats, visitors are encouraged to call the +1-(888)-351-4098 number. Generally, when scammers behind these websites are contacted, they try to sell unnecessary software to unsuspecting users or trick them into paying for bogus services.

They often ask users for permission to access their computers remotely. In such cases, they use this access to steal sensitive information, infect computers with malware (e.g., ransomware, Trojan), and for other malicious purposes. In any case, ignore all technical support scams.

As mentioned, users often arrive at these pages due to PUAs installed on the browser and/or computer that promote (open) them.

PUAs are designed to open untrusted pages (including technical support scams), collect various user-system information, and serve advertisements. They gather details such as IP addresses, geolocations, addresses of visited websites, entered search queries, etc. In some cases, they are capable of accessing sensitive information as well.

The developers sell gathered data to third parties (potentially, cyber criminals) or misuse it to generate revenue in other ways. Additionally, PUAs can be designed to serve coupons, banners, pop-ups, surveys and other types of ads. When clicked, these can open dubious websites, and sometimes execute scripts designed to cause download/installation of PUAs.

Threat Summary:
Name Windows Defender - Security Warning technical support scam
Threat Type Phishing, Scam, Social Engineering, Fraud.
Fake Claim Website has detected Spyware, Trojan and error.
Tech Support Scammer Phone Number +1-(888)-351-4098, +1-833-930-2284, +1-866-849-1382
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 Combo Cleaner.
▼ Download Combo Cleaner
To use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by Rcs Lt, the parent company of PCRisk.com read more.

"Trojan Spyware Alert", "ERROR # 0x6a4-0xf9fx3999", "Activation Failed! (Error Code 001)" and "Windows Error Code: DLL011150" are examples of other technical support scams.

As mentioned, scammers behind these websites attempt to deceive unsuspecting visitors into believing that there is something wrong with the operating system/computer, and calling the provided number. Their main goal is to extort money or to gain access to computers remotely. If a browser opens websites of this type, PUA are probably installed on it.

How did potentially unwanted applications install on my computer?

PUAs are often downloaded/installed together with other products. This deceptive marketing technique of pre-packing regular software with unwanted or malicious additions is called "bundling".

By rushing through download/installation of software (e.g. ignoring terms, skipping steps and sections, using "Quick/Express" settings, etc.) many users risk unintentionally allowing bundled content into their devices. Intrusive advertisements proliferate PUAs as well.

When clicked, the ads can execute scripts to download/install these applications without users' permission. Some PUAs have "official" download web pages from which they can be downloaded.

How to avoid installation of potentially unwanted applications

Download software and files from official websites and via direct links. It is not safe to use torrent clients, eMule (or other Peer-to-Peer networks), third party downloaders, unofficial websites or other sources of this kind. Avoid third party installers. Check "Advanced", "Custom" and other settings, and decline offers to download or install unwanted software.

Do not click ads that are displayed on dubious websites, since they can open other untrusted websites or even cause unwanted downloads and installations. Remove any unwanted, suspicious applications (extensions, add-ons, and plug-ins) that are installed on the browser.

The same should be applied to programs of this kind that are installed on the operating system. If your computer is already infected with PUAs, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate them.

The appearance of "Windows Defender - Security Warning" pop-up scam (GIF):

Appearance of Windows Defender - Security Warning scam

Text presented in initial pop-up window:

Windows Firewall Protection

 

Microsoft
Trojan Spyware Alert - Error Code: #0x898778
Access to this PC has been blocked for security reasons.

 

Contact Windows Support: +1-(888)-351-4098

 

Threat Detected - Trojan Spyware

App: Ads.financetrack(1).exe

 

Run Anyway Back to Safety

Text in the second pop-up window:

Windows Defender - Security Warning
** ACCESS TO THIS PC HAS BEEN BLOCKED FOR SECURITY REASONS **

 

Your computer has alerted us that it has been infected with a Trojan Spyware. The following data has been compromised.

 

> Email Credentials
> Banking Passwords
> Facebook Login
> Pictures & Documents

 

Windows Defender Scan has found potentially unwanted Adware on this device that can steal your passwords, online identity, financial information, personal files, pictures or documents.

 

You must contact us immediately so that our engineers can walk you through the removal process over the phone.

 

Call Microsoft Support immediately to report this threat, prevent identity theft and unlock access to this device.

 

Closing this window will put your personal information at risk and lead to a suspension of your Windows Registration.

 

Call Microsoft Support: +1-(888)-351-4098 (USA Toll Free)

 

OK Cancel

Text in the background:

Error: Unknown System Failure!

 

Contact Support

 

+1-(888)-351-4098

 

(USA Toll Free)

 

LIVE CHAT
 

 Windows Defender Scan

 

 Settings Help

 

You Are Protected
Protection Updates: Current

 

Last Scan: Not available | Quick Scan

 

Licenses Used: 1 of 5 | Install on Another Device

 

Security Protected Identity Protected Performance Protected Firewall Protected

 

SUBSCRIPTION STATUS: 2 Days Remaining

Another variant of "Windows Defender - Security Warning" pop-up scam:

Microsoft Windows Defender - Security Warning pop-up scam (2020-12-02)

Another example of "Windows Defender - Security Warning" pop-up scam:

Windows Defender - Security Warning pop-up scam (2021-09-17)

Text presented within:

Windows Defender - Security Warning

App: Ads.fiancetrack(2).dll
Threat detected: Trojan Spyware

Windows was blocked due to questionable activity.

Contact Technical Support: +1-833-930-2284
[Continue] [Back]

Appearance of this "Windows Defender - Security Warning" scam variant (GIF):

Windows Defender - Security Warning pop-up scam (GIF - 2021-09-17)

Instant automatic malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Combo Cleaner is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
▼ DOWNLOAD Combo Cleaner 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 Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by Rcs Lt, the parent company of PCRisk.com read more.

Quick menu:

Removal of potentially unwanted applications:

Windows 11 users:

Accessing Apps and Features in Windows 11

Right-click on the Start icon, select Apps and Features. In the opened window search for the application you want to uninstall, after locating it, click on the three vertical dots and select Uninstall.

Windows 10 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.

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.

macOS (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:

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 windows defender - security warning technical support scam, 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 windows defender - security warning technical support scam 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 windows defender - security warning technical support scam, 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.

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 windows defender - security warning technical support scam, 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

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 windows defender - security warning technical support scam from your computer, please ask for assistance in our malware support forum.

Post a comment:
If you have additional information on windows defender - security warning technical support scam or it's removal please share your knowledge in the comments section below.

Click to post a comment

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.

Our malware removal guides are free. However, if you want to support us you can send us a donation.

About PCrisk

PCrisk logo

PCrisk is a cyber security portal, informing Internet users about the latest digital threats. Our content is provided by security experts and professional malware researchers. Read more about us.

Removal Instructions in other languages
Malware activity

Global malware activity level today:

Medium threat activity

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

QR Code
Windows Defender - Security Warning technical support scam QR code
Scan this QR code to have an easy access removal guide of Windows Defender - Security Warning technical support scam on your mobile device.
We Recommend:

Get rid of Windows malware infections today:

▼ REMOVE IT NOW
Download Combo Cleaner

Platform: Windows

Editors' Rating for Combo Cleaner:
Editors ratingOutstanding!

[Back to Top]

To use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by Rcs Lt, the parent company of PCRisk.com read more.