Remove apps that open "Windows Defender - Security Warning" and similar scams
Written by Tomas Meskauskas on
(updated)
"Windows Defender - Security Warning" removal instructions
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.
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.
| 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 |
| 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. |
"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):
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:
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.
Quick menu:
- What is "Windows Defender - Security Warning"?
- STEP 1. Uninstall deceptive applications using Control Panel.
- STEP 2. Remove rogue extensions from Google Chrome.
- STEP 3. Remove potentially unwanted plug-ins from Mozilla Firefox.
- STEP 4. Remove rogue extensions from Safari.
- STEP 5. Remove rogue plug-ins from Microsoft Edge.
- STEP 6. Remove adware from Internet Explorer.
Removal of potentially unwanted applications:
Windows 7 users:
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:
Click Start, choose Settings and click Control Panel. Locate and click Add or Remove Programs.
Windows 10 and Windows 8 users:
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:
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.
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:
Remove malicious extensions from Google Chrome:
Click the 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.
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 (at the top right corner of Google Chrome) and select Settings. Scroll down to the bottom of the screen. Click the Advanced… link.
After scrolling to the bottom of the screen, click the Reset (Restore settings to their original defaults) button.
In the opened window, confirm that you wish to reset Google Chrome settings to default by clicking the Reset button.
Remove malicious plug-ins from Mozilla Firefox:
Click the Firefox menu 
(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.
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, in the opened menu, click Help.
Select Troubleshooting Information.
In the opened window, click the Refresh Firefox button.
In the opened window, confirm that you wish to reset Mozilla Firefox settings to default by clicking the Refresh Firefox button.
Remove malicious extensions from Safari:
Make sure your Safari browser is active, click Safari menu, and select Preferences....
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...
In the opened window select all history and click the Clear History button.
Remove malicious extensions from Microsoft Edge:
Click the Edge 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.
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 (at the top right corner of Microsoft Edge) and select Settings.
In the opened settings menu select Reset settings.
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.
- If this did not help, follow these alternative instructions explaining how to reset the Microsoft Edge browser.
Remove malicious add-ons from Internet Explorer:
Click the "gear" 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".
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.
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.
Windows 8 users: Open Internet Explorer and click the gear icon. Select Internet Options.
In the opened window, select the Advanced tab.
Click the Reset button.
Confirm that you wish to reset Internet Explorer settings to default by clicking the Reset button.
Summary:
Commonly, 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.
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Outstanding!
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