Firewall Breach Detected" virus: what it is and how to remove it

"Firewall Breach Detected" alert is a fake "error 0x8007042C" warning notifying that Microsoft has detected a security breach from your IP address. It may look completely legitimate since scammers tend to intimidate victims by claiming that it may lead to data loss, identity theft, loss of passwords for social networking platforms and credit card details.

Facts checked October 7, 2026. Removal steps tested on Windows 11 (26H2) and checked against Microsoft's and the browser makers' current documentation. Sections marked as our earlier report are the original text: they describe the threat as it was then and have not been reviewed since. The 2026 status, the removal steps and the questions are current.

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A scan of the PC is a quick way to confirm that nothing installed is behind the dieviren.de redirects.

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Firewall Breach Detected" virus: firewall breach detected virus is promoted via phishing websites
Firewall Breach Detected" virus as our 2017 report showed it.

Firewall Breach Detected" virus: summary

Detection namesNo Microsoft detection name is known
DistributionNot recorded in the old report
DamageNot recorded in the old report
NameFirewall Breach Detected" virus
TypeAdware extension
SymptomsRedirects to an unknown domain
Removal

Scan the PC with security software to find and remove the malware and anything installed with it. Fortect scans Windows for malware and repairs the system files and settings it damaged.

Remove it nowTo use the full-featured product, you have to purchase a license for Fortect. The scan is free.
Show 6 more facts
Evidence4 write-ups by security sites; details still limited
Domainsdieviren.de
Ads shown asRedirects through ad pages
BrowsersChrome, Edge and Firefox
First seen26 October 2017
Facts checked7 October 2026

Is Firewall Breach Detected" virus dangerous?

From our report of Oct 2017 · not reviewed since

"Firewall Breach Detected" virus displays a fake alarm message to misguide computer users

"Firewall Breach Detected" alert is a fake "error 0x8007042C" warning notifying that Microsoft has detected a security breach from your IP address.

It may look completely legitimate since scammers tend to intimidate victims by claiming that it may lead to data loss, identity theft, loss of passwords for social networking platforms and credit card details. The developers urge to contact "Microsoft Network Security Advisor" via toll-free +1 844 699 8351 number.

Most people get confused or scared due to the atmosphere created to consult "as soon as possible" and as a result, unconsciously provide their personal number to the criminals. Thus, if you encountered a redirect to this alert pop-up, immediately close the window/tab and remove "Firewall Breach Detected" using a security software of your choice.

You should be aware that fake warnings are created to collect victims' mobile numbers and later, offer their "help" to fix the nonexistent problem. Cybercriminals might choose between several ways to swindle money:

If you click on any ads promoted by this warning pop-up, they might redirect you to suspicious websites containing malware-infected links or even trigger an automatic installation of one. Therefore, you should avoid clicking on vague ads and start "Firewall Breach Detected" removal. We strongly recommend using or any other trustworthy security system.

  • Insist on purchasing sponsored or expensive security software that is unnecessary for you;
  • Ask to provide access to manage your computer remotely and infect it with high-risk computer infections to continuously charge money for their services;
  • Distribute malware through spam text messages.
Firewall Breach Detected" virus: firewall breach detected virus is promoted via phishing websites
Firewall Breach Detected" virus in our 2017 report.
Firewall Breach Detected" virus: firewall breach detected virus is a warning pop up
Firewall Breach Detected" virus in our 2017 report.

From our report of Oct 2017 · not reviewed since

Kill "Firewall Breach Detected" warning pop-up automatically

Our IT professionals suggest you to remove "Firewall Breach Detected" with the help of a security application.

As mentioned above, scammers might have infected your computer with malware remotely. To make sure that your system is entirely safe, you have to get rid of all corrupted files. Thus, trying to detect the unknown virus might become an impossible mission.

Instead, you should download a reliable security program and run a full system scan. It will help to uninstall all types of malware found and maintain your security in the future.

However, if you have still decided to use your manual "Firewall Breach Detected" removal option, follow the guidelines at the end of this article. Make sure to uninstall the adware safely, in order not to do even more damage.

How Firewall Breach Detected" virus got into your browser

From our report of Oct 2017 · not reviewed since

You might encounter such scam due to the presence of a potentially unwanted program (PUP) or another plug-in in your computer.

It sneaks into your system if you choose Quick/Recommended installation process and do not decline to install the adware bundled together. Dieviren.de team warns that such occurrences are extremely frequent.

Developers intentionally hide the information about the PUP that comes as a package with other free software. Therefore, you should avoid downloading applications from unauthorized developers. If you do so, always select Advanced or Custom settings and un-tick all preselected boxes allowing to install the adware.

Besides, potentially unwanted programs (PUPs) spread via intrusive ads. Developers try their best to attract users into clicking on them. Never trust delusional advertisements offering free coupons, quickly earned prizes or secrets of an effective diet.

Check your browser and PC

  • Address: dieviren.de

How to remove Firewall Breach Detected" virus

Do the browser steps in every browser and profile on the PC, then check Windows for the program that installed the extension.

  1. Step 1: Remove extensions you did not add

    In Chrome open chrome://extensions, in Edge edge://extensions, and in Firefox the menu > Extensions and themes.

    Remove every extension you do not remember adding, especially search, new tab, coupon, PDF, weather or video downloader add-ons. Check every browser and every profile, because each keeps its own list.

    If an extension has no Remove button or comes back, a browser policy holds it (see "Managed by your organization" in the procedure below). The pages are the same on Windows 11 and Windows 10.

    Chrome menu with Extensions and Manage extensions highlighted
    Chrome on Windows 11: More > Extensions > Manage extensions.

    Full procedure with screenshots: Remove a browser extension

  2. Step 2: Uninstall programs you did not mean to install

    Firewall Breach Detected" virus rarely comes alone: it is usually installed by, or together with, a free program. In Windows 11 open Settings > Apps > Installed apps, in Windows 10 Settings > Apps > Apps & features, and sort by install date.

    Uninstall every entry from the day the trouble began that you did not install on purpose, for example a download manager, a converter or a browser you never chose.

    Keep drivers and entries from Microsoft, Intel, AMD, NVIDIA or your PC's maker unless you are sure.

    Full procedure with screenshots: Uninstall a program or app in Windows On uGetFix

  3. Step 3: Reset the browser

    A reset removes what the steps above could miss:

    • changed start pages
    • site permissions
    • hidden settings

    In Chrome open Settings > Reset settings > Restore settings to their original defaults; in Edge Settings > Reset settings; in Firefox Help > More troubleshooting information > Refresh Firefox.

    Tip: Bookmarks and saved passwords stay, while extensions are turned off and the search engine and start page return to the defaults.

    Reset every browser on the PC, including Edge, which Windows 11 and Windows 10 always have.

    Chrome Settings page with the Reset settings section open
    Chrome on Windows 11: Settings > Reset settings.

    Full procedure with screenshots: Reset a browser and fix a hijacked search engine

  4. Step 4: Scan the PC, then run the offline scan

    A scan finds the parts of Firewall Breach Detected" virus that the manual steps cannot see. In Windows Security > Virus & threat protection > Scan options, start a Full scan and quarantine what it reports.

    Follow it with Microsoft Defender Antivirus (offline scan) > Scan now, which restarts the PC and checks the disk while Windows and the malware are not running.

    It takes about 15 minutes and works the same in Windows 11 and Windows 10. If either scan finds something, run the full scan again after removal until it comes back clean.

    Windows Security Scan options with Microsoft Defender Antivirus offline scan selected
    Windows 11: Windows Security > Virus & threat protection > Scan options.

    Full procedure with screenshots: Run a Microsoft Defender Offline scan

Instructions for each browser and system

The detailed steps for every browser and system this guide covers. Open the one you use.

Uninstall from Windows

Check your computer for suspicious programs that may have sneaked into the system without your notice. Uninstall every program you suspect to be causing "Firewall Breach Detected" pop-ups.

Uninstall from Windows 10/8:

  1. Type Control Panel into the Windows search box and open the result.
  2. Under Programs, select Uninstall a program.Uninstall from Windows 10/8

Uninstall from Windows 7/XP:

  1. Click on Windows Start > Control Panel (Windows XP users should click on Add/Remove Programs).
  2. In Control Panel, select Programs > Uninstall a program.Uninstall from Windows 7/XP

Remove the unwanted program:

  1. In the Programs and Features window, look for any recently installed suspicious entries, select them, and click Uninstall.
  2. If User Account Control appears, click Yes to confirm, then complete the removal.Uninstall the unwanted program from Windows
Remove from Google Chrome

Reset Google Chrome to block unwanted tech support scam ads.

Delete malicious extensions from Google Chrome:

  1. Open Google Chrome, click on the Menu (three vertical dots at the top-right corner) and select More tools > Extensions.
  2. In the newly opened window, you will see all the installed extensions. Uninstall all suspicious extensions related to the unwanted program by clicking Remove.Remove extensions from Chrome

Clear cache and web data from Chrome:

  1. Click on Menu and pick Settings.
  2. Under Privacy and security, select Clear browsing data.
  3. Select Browsing history, Cookies and other site data, as well as Cached images and files.
  4. Click Clear data.Clear cache and web data from Chrome

Change your homepage:

  1. Click menu and choose Settings.
  2. Look for a suspicious site in the On startup section.
  3. Click on Open a specific or set of pages and click on three dots to find the Remove option.

Reset Google Chrome:

If the previous methods did not help you, reset Google Chrome to eliminate all the unwanted components:

  1. Click on Menu and select Settings.
  2. In the Settings, scroll down and click Advanced.
  3. Scroll down and locate Reset and clean up section.
  4. Now click Restore settings to their original defaults.
  5. Confirm with Reset settings.Reset Chrome 2
Remove from Microsoft Edge

Delete unwanted extensions from MS Edge:

  1. Select Menu (three horizontal dots at the top-right of the browser window) and pick Extensions.
  2. From the list, pick the extension and click on the Gear icon.
  3. Click Remove.Remove extensions from Edge

Clear cookies and other browser data:

  1. Click on the Menu (three horizontal dots at the top-right of the browser window) and select Settings > Privacy, search, and services..
  2. Under Clear browsing data, pick Choose what to clear.
  3. Select Cookies and other site data and Cached images and files. (apart from passwords, although you might want to include Media licenses as well, if applicable) and click on Clear.Clear Edge browsing data

Restore new tab and homepage settings:

  1. Click the menu icon and choose Settings.
  2. Then find On startup section.
  3. Click Remove next to any suspicious startup page.

Reset MS Edge if the above steps did not work:

  1. Press on Ctrl + Shift + Esc to open Task Manager.
  2. Click on More details arrow at the bottom of the window.
  3. Select Details tab.
  4. Now scroll down and locate every entry with Microsoft Edge name in it. Right-click on each of them and select End Task to stop MS Edge from running.Reset MS Edge
Instructions for Chromium-based Edge

Delete extensions from MS Edge (Chromium):

  1. Open Edge and click select Settings > Extensions.
  2. Delete unwanted extensions by clicking Remove.Remove extensions from Chromium Edge

Clear cache and site data:

  1. Click on Menu and go to Settings.
  2. Select Privacy, search and services.
  3. Under Clear browsing data, pick Choose what to clear.
  4. Under Time range, pick All time.
  5. Select Clear now.Clear browser data from Chroum Edge

Reset Chromium-based MS Edge:

  1. Click on Menu and select Settings.
  2. On the left side, pick Reset settings.
  3. Select Restore settings to their default values.
  4. Confirm with Reset.
  5. This will disable extensions and reset startup pages but will not delete bookmarks, saved passwords, or browsing history.Reset Chromium Edge
Remove from Mozilla Firefox (FF)

Remove dangerous extensions:

  1. Open Mozilla Firefox browser and click on the Menu (three horizontal lines at the top-right of the window).
  2. Select Add-ons.
  3. In here, select the unwanted extension and click Remove.Remove extensions from Firefox

Reset the homepage:

  1. Click three horizontal lines at the top right corner to open the menu.
  2. Choose Settings.
  3. Under Home, set your preferred homepage and new tab settings.

Clear cookies and site data:

  1. Click Menu and pick Settings.
  2. Go to Privacy & Security section.
  3. Scroll down to locate Cookies and Site Data.
  4. Click on Clear Data...
  5. Select Cookies and Site Data and Temporary cached files and pages, then click Clear.Clear cookies and site data from Firefox

Reset Mozilla Firefox

If clearing the browser as explained above did not help, reset Mozilla Firefox:

  1. Open Mozilla Firefox browser and click the Menu.
  2. Go to Help and then choose Troubleshooting Information.Reset Firefox 1
  3. Under Give Firefox a tune up section, click on Refresh Firefox...
  4. Once the pop-up shows up, confirm the action by pressing on Refresh Firefox.Reset Firefox 2
Delete from Safari

Remove dangerous extensions:

  1. Open Safari, click Safari in the menu at the top-left of the screen, and select Preferences.
  2. Go to the Extensions tab, look for any suspicious entries, and click Uninstall to remove them.Remove extensions from Safari

Clear history and website data:

  1. Click Safari in the menu and pick Clear History.
  2. Set Clear to all history and confirm with Clear History.Clear history from Safari

Reset Safari:

  1. Click Safari in the menu and select Preferences > Advanced.
  2. Enable Show Develop menu in menu bar.
  3. From the menu bar, click Develop and select Empty Caches.Reset Safari
Delete from macOS

Remove the unwanted application:

  1. From the menu bar, select Go > Applications.
  2. In the Applications folder, look for any suspicious entries, then drag them to Trash (or right-click and pick Move to Trash).Uninstall from Mac

Delete leftover files and folders:

  1. Select Go > Go to Folder.
  2. Enter /Library/Application Support and remove any suspicious folders related to the unwanted program.
  3. Repeat the same check in the /Library/LaunchAgents and /Library/LaunchDaemons folders, deleting any suspicious entries.Delete leftover files from Mac
  4. Finally, empty the Trash to permanently remove the leftovers.
Reset Internet Explorer

Remove dangerous add-ons:

  1. Open Internet Explorer, click on the Gear icon (IE menu) on the top-right corner of the browser
  2. Pick Manage Add-ons.
  3. You will see a Manage Add-ons window. Here, look for suspicious plugins. Click on these entries and select Disable.Remove add-ons from Internet Explorer

Change your homepage if it was altered:

  1. Open IE and click on the Gear icon.
  2. Select Internet Options.
  3. In the General tab, delete the Home page address and replace it by your preferred one (for example, Google.com).
  4. Click Apply and then select OK.Reset IE homepage

Delete temporary files:

  1. Press on the Gear icon and select Internet Options.
  2. Under Browsing history, click Delete...
  3. Select relevant fields and press Delete.Clear temporary files from Internet Explorer

Reset Internet Explorer:

  1. Click on Gear icon > Internet options and select Advanced tab.
  2. Select Reset.
  3. In the new window, check Delete personal settings and select Reset.Reset Internet Explorer

Protect your privacy - employ a VPN

There are several ways how to make your online time more private - you can access an incognito tab.

However, there is no secret that even in this mode, you are tracked for advertising purposes. There is a way to add an extra layer of protection and create a completely anonymous web browsing practice with the help of VPN. This software reroutes traffic through different servers, thus leaving your IP address and geolocation in disguise.

Besides, it is based on a strict no-log policy, meaning that no data will be recorded, leaked, and available for both first and third parties. The combination of a secure web browser and VPN will let you browse the Internet without a feeling of being spied or targeted by criminals.

No backups? No problem. Use a data recovery tool

If you wonder how data loss can occur, you should not look any further for answers - human errors, malware attacks, hardware failures, power cuts, natural disasters, or even simple negligence.

In some cases, lost files are extremely important, and many straight out panic when such an unfortunate course of events happen. Due to this, you should always ensure that you prepare proper data backups on a regular basis.

If you were caught by surprise and did not have any backups to restore your files from, not everything is lost. is one of the leading file recovery solutions you can find on the market - it is likely to restore even lost emails or data located on an external device.

Questions about Firewall Breach Detected" virus

Why does my browser keep going to dieviren.de?

Something is sending it there. On one site only, that site's ads are the cause and leaving the site ends it.

On many different sites, the usual causes are an extension you installed with something else, a site you once allowed to send notifications, or an ad-supported program in Windows that changes how the browser behaves. dieviren.de itself is only a stop on the way: it records the visit and forwards you to whatever advertiser pays most.

Check the extensions page, then the list of sites allowed to send notifications, then Installed apps sorted by date. Removing the cause stops the redirects; blocking the domain alone usually does not, because the network moves to a new one.

Did dieviren.de install a virus on my PC?

Very unlikely, unless you downloaded and opened something from the pages it led to. Redirect domains such as dieviren.de sell your visit to advertisers; they do not need to install anything to make money.

What can be installed is the thing that causes the redirects in the first place, such as an extension or an ad-supported program that came with free software. That is why the checks in this guide look at extensions, notification permissions and Installed apps.

A full scan with Microsoft Defender afterwards gives you a clear answer about the rest of the PC. If the scan is clean and the redirects stop after removing the cause, you are done.

Why does Firewall Breach Detected" virus show me ads?

Because that is its whole purpose. Firewall Breach Detected" virus is an adware extension, and its operators are paid for every ad it displays and every click it gets. In this case the ads take the form of redirects through ad pages.

They are chosen by ad networks that accept almost any advertiser, which is why so many look like warnings or prizes. The ads are not a sign that your PC is broken or infected with something worse; they are a sign that something on it, or in the browser, has permission to advertise. Removing that permission or program stops them.

Do I have to clean every browser?

Yes, if you use more than one. We saw Firewall Breach Detected" virus in Chrome, Edge and Firefox, and each browser keeps its own extensions, notification permissions and settings. Chrome and Edge share the same extension format, so one installer can add the same adware to both, while Firefox has its own add-ons.

Check every browser on the PC, including ones you rarely open. If you sync a browser with an account, clean it while signed in, so that the removal reaches your other computers rather than the adware returning from them.

How do I know the ads come from Firewall Breach Detected" virus?

Look for redirects to dieviren.de. That is the trace Firewall Breach Detected" virus leaves, and it shows up as redirects through ad pages. Ads that appear on every site, including ones that never carried ads before, point to something on your PC or in the browser rather than to the sites themselves.

A quick test is a private window, where extensions are off by default: if the ads disappear there, an extension is responsible. If they appear even with the browser closed, the source is a notification permission or a program in Windows.

I clicked on one of the ads. Am I infected?

Probably not. Clicking an ad usually only opens a page, and a page cannot install programs on an up-to-date Windows PC without your help.

You are at risk only if you then downloaded and ran a file, allowed notifications, entered card or login details, or called a phone number shown on the page. Delete any download and run a full and offline scan.

Change passwords you typed, from a clean device. Call your bank if you gave card details. If you called a number or allowed remote access, see the next question.

An ad showed a phone number and I called it. What now?

The number belongs to scammers, not to Microsoft or an antivirus company. If you only talked, hang up and do not call back. If you let them connect to the PC, disconnect it from the internet, uninstall the remote access program they used, such as AnyDesk, TeamViewer, ScreenConnect or UltraViewer, and run a full and offline scan.

If you paid or gave bank details, call your bank at once on the number printed on your card. Change any passwords you typed while they were connected, and report the call.

Does adware steal passwords?

Ordinary adware is built to show ads, not to steal logins, and most of it never touches saved passwords. The line is blurry, though. Extensions that can read every page could capture what you type, and adware ads sometimes lead to phishing pages that ask for passwords directly.

If you entered credentials on a page reached through an ad, change that password from a clean device and turn on two-step verification. Otherwise, removing adware extension and clearing cookies is usually enough.

Why didn't my antivirus catch Firewall Breach Detected" virus?

Many security products do not block adware or notification sites by default, because users often agreed to them, even through a misleading prompt. Notification spam installs nothing at all, so there is no file to detect.

In Windows 11 you can make Microsoft Defender block potentially unwanted apps: open Windows Security > App & browser control > Reputation-based protection settings and turn on Potentially unwanted app blocking. If notifications caused the pop-ups, no scanner will report them; the fix is in the browser's site settings.

Will Fortect remove Firewall Breach Detected" virus?

Fortect scans Windows for malware and unwanted programs and repairs the system files and settings they change, and its free scan shows what it finds on your PC before you decide anything.

For Firewall Breach Detected" virus, follow the plan above as well: the browser steps take back permissions and settings that no scanner treats as a threat, and uninstalling the program that brought it removes the source.

Run Microsoft Defender's full scan and, if anything was found, its offline scan as a second opinion. If the symptoms are gone after the plan and both scans are clean, there is nothing more to do.

Sources

  1. Microsoft: Tech support scams (read October 7, 2026)
  2. Microsoft Technet - Windows Security Blog: Tech support scams persist with increasingly crafty techniques (read October 7, 2026)
  3. Dieviren: Dieviren (read October 7, 2026)
  4. Google Chrome Help: Use notifications to get alerts (no longer online) (read October 7, 2026)
  5. FTC: How to recognize, remove and avoid malware (read October 7, 2026)

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