System Security Tool ads: what it is and how to remove it
System Security Tool virus is an adware that is capable of generating legitimate-looking ads that claim that the computer's system is in critical condition, and encourage users to contact the remote tech support in order to solve this problem. In reality, there is no actual threat on your computer.
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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System Security Tool ads: summary
| Detection names | No Microsoft detection name is known |
|---|---|
| Distribution | Not recorded in the old report |
| Damage | Not recorded in the old report |
| Name | System Security Tool |
| Type | Adware extension |
| Symptoms | An unknown program in Installed apps |
| 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 4 more facts
| Evidence | One write-up by a security site; details still limited |
|---|---|
| Program | System Security Tool |
| First seen | 1 February 2021 |
| Facts checked | 7 October 2026 |
Is System Security Tool ads dangerous?
From our report of Feb 2021 · not reviewed since
System Security Tool is a potentially unwanted program that shows fake advertisements
System Security Tool virus is an adware that is capable of generating legitimate-looking ads that claim that the computer's system is in critical condition, and encourage users to contact the remote tech support in order to solve this problem. In reality, there is no actual threat on your computer.
Furthermore, if you decide to trust on System Security Tool virus and call the number provided in the fake security notification, you will not be connected to the technician but merely to a salesperson waiting to sell you an unnecessary security contract or offer other services. The scare tactics that these security support scammers use often work and the victims purchase the supposed security support contracts.
However, we have to warn you not to try contacting the given number, not to mention buying the suggested products, because you may simply be scammed. It will detect and remove System Security Tool and any other suspicious components from your PC.
There are also other ways of distinguishing fake ads from legitimate system notifications if you suspect you have been a victim of a System Security Tool hijack. First, you can try closing your browser and see if the notifications still appear on your screen. Even better, you can disconnect your device from the network and monitor your computer's activity.
If the notifications stop appearing you can be sure that they were simply System Security Tool ads, and you should not worry about the safety of your computer too much. However, as mentioned before, you should make sure that the system is virus-free by scanning your computer with some reputable virus-fighting utility, such as or .
Finally, you should specifically examine the content of the System Security Tool notifications. It varies minimally throughout the different ads; therefore, it is easily recognizable. Take a look at the following example:
If you notice ads featuring similar content occurring on your computer you most likely have adware residing on your PC. It is essential to take care of the System Security Tool removal if you want to keep using your computer safely and uninterruptedly. Also, if you notice that your computer is still performing worse than before after all problems have been terminated, you may need to fix your system.

From our report of Feb 2021 · not reviewed since
More from our earlier report on System Security Tool
- Firewall Detected Potential Threads on Your Computer Warning.
- Windows Security Essentials wasn't able to block the threats.
- Windows detected several threats that will compromise your privacy and harm your computer.
- Error Code: 0x000007c, Windows couldn't install the definition updates.
- More Information & Support Please contact 1-800-754-3403
How System Security Tool ads got into your browser
From our report of Feb 2021 · not reviewed since
Even though some features of this program slightly differ from other programs of this particular category, the ways through which it is distributed are virtually the same.
This adware is distributed through a deceptive marketing method, also referred to as "bundling".
"Bundling" occurs when two programs are added to the same software package, and the user downloads them both in one go. You can imagine how useful such a feature can be to the creators of potentially unwanted programs.
Their malicious creations can enter the users' computers unnoticed and silently carry out questionable activities. But this stealthy hijack can as well be avoided if you spare some more time for the new software installation process.
Firstly, choose your source of downloading programs wisely. Secondly, before heading straight to the installation process, let your antivirus scan the downloaded application to determine its reliability. Finally, always opt for the advanced installation settings to monitor and manage all the optional installs.
How to remove System Security Tool ads
How to remove the System Security Tool extension
Do the browser steps in every browser and profile on the PC, then check Windows for the program that installed the extension.
Step 1: Remove extensions you did not add
In Chrome open
chrome://extensions, in Edgeedge://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 on Windows 11: More > Extensions > Manage extensions. Full procedure with screenshots: Remove a browser extension
Step 2: Uninstall System Security Tool
System Security Tool is removed like any other program, from the list of installed apps. In Windows 11 that is Settings > Apps > Installed apps, in Windows 10 Settings > Apps > Apps & features, and in both you can also use Control Panel > Programs and Features.
Select System Security Tool, click Uninstall and follow the uninstaller to the end. Then look at the entries just above and below it when the list is sorted by date: bundled programs install at the same minute.
Full procedure with screenshots: Uninstall a program or app in Windows On uGetFix
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 on Windows 11: Settings > Reset settings. Full procedure with screenshots: Reset a browser and fix a hijacked search engine
Step 4: Scan the PC, then run the offline scan
A scan finds the parts of System Security Tool 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 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
If you want to remove adware, follow these steps:
Uninstall from Windows 10/8:
- Type Control Panel into the Windows search box and open the result.
- Under Programs, select Uninstall a program.

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

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

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

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

Change your homepage:
- Click menu and choose Settings.
- Look for a suspicious site in the On startup section.
- 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:
- Click on Menu and select Settings.
- In the Settings, scroll down and click Advanced.
- Scroll down and locate Reset and clean up section.
- Now click Restore settings to their original defaults.
- Confirm with Reset settings.

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

Clear cookies and other browser data:
- Click on the Menu (three horizontal dots at the top-right of the browser window) and select Settings > Privacy, search, and services..
- Under Clear browsing data, pick Choose what to clear.
- 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.

Restore new tab and homepage settings:
- Click the menu icon and choose Settings.
- Then find On startup section.
- Click Remove next to any suspicious startup page.
Reset MS Edge if the above steps did not work:
- Press on Ctrl + Shift + Esc to open Task Manager.
- Click on More details arrow at the bottom of the window.
- Select Details tab.
- 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.

Delete extensions from MS Edge (Chromium):
- Open Edge and click select Settings > Extensions.
- Delete unwanted extensions by clicking Remove.

Clear cache and site data:
- Click on Menu and go to Settings.
- Select Privacy, search and services.
- Under Clear browsing data, pick Choose what to clear.
- Under Time range, pick All time.
- Select Clear now.

Reset Chromium-based MS Edge:
- Click on Menu and select Settings.
- On the left side, pick Reset settings.
- Select Restore settings to their default values.
- Confirm with Reset.
- This will disable extensions and reset startup pages but will not delete bookmarks, saved passwords, or browsing history.

Remove from Mozilla Firefox (FF)
Use these instructions if you want to delete the potentially unwanted program from Mozilla Firefox:
Remove dangerous extensions:
- Open Mozilla Firefox browser and click on the Menu (three horizontal lines at the top-right of the window).
- Select Add-ons.
- In here, select the unwanted extension and click Remove.

Reset the homepage:
- Click three horizontal lines at the top right corner to open the menu.
- Choose Settings.
- Under Home, set your preferred homepage and new tab settings.
Clear cookies and site data:
- Click Menu and pick Settings.
- Go to Privacy & Security section.
- Scroll down to locate Cookies and Site Data.
- Click on Clear Data...
- Select Cookies and Site Data and Temporary cached files and pages, then click Clear.

Reset Mozilla Firefox
If clearing the browser as explained above did not help, reset Mozilla Firefox:
- Open Mozilla Firefox browser and click the Menu.
- Go to Help and then choose Troubleshooting Information.

- Under Give Firefox a tune up section, click on Refresh Firefox...
- Once the pop-up shows up, confirm the action by pressing on Refresh Firefox.

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

Clear history and website data:
- Click Safari in the menu and pick Clear History.
- Set Clear to all history and confirm with Clear History.

Reset Safari:
- Click Safari in the menu and select Preferences > Advanced.
- Enable Show Develop menu in menu bar.
- From the menu bar, click Develop and select Empty Caches.

Delete from macOS
Remove the unwanted application:
- From the menu bar, select Go > Applications.
- In the Applications folder, look for any suspicious entries, then drag them to Trash (or right-click and pick Move to Trash).

Delete leftover files and folders:
- Select Go > Go to Folder.
- Enter /Library/Application Support and remove any suspicious folders related to the unwanted program.
- Repeat the same check in the /Library/LaunchAgents and /Library/LaunchDaemons folders, deleting any suspicious entries.

- Finally, empty the Trash to permanently remove the leftovers.
Reset Internet Explorer
Remove dangerous add-ons:
- Open Internet Explorer, click on the Gear icon (IE menu) on the top-right corner of the browser
- Pick Manage Add-ons.
- You will see a Manage Add-ons window. Here, look for suspicious plugins. Click on these entries and select Disable.

Change your homepage if it was altered:
- Open IE and click on the Gear icon.
- Select Internet Options.
- In the General tab, delete the Home page address and replace it by your preferred one (for example, Google.com).
- Click Apply and then select OK.

Delete temporary files:
- Press on the Gear icon and select Internet Options.
- Under Browsing history, click Delete...
- Select relevant fields and press Delete.

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

Do not let government spy on you
The government has many issues in regards to tracking users' data and spying on citizens, so you should take this into consideration and learn more about shady information gathering practices.
Avoid any unwanted government tracking or spying by going totally anonymous on the internet.
You can choose a different location when you go online and access any material you want without particular content restrictions. You can easily enjoy internet connection without any risks of being hacked by using VPN.
Control the information that can be accessed by government any other unwanted party and surf online without being spied on. Even if you are not involved in illegal activities or trust your selection of services, platforms, be suspicious for your own security and take precautionary measures by using the VPN service.
Backup files for the later use, in case of the malware attack
Computer users can suffer from data losses due to cyber infections or their own faulty doings.
Ransomware can encrypt and hold files hostage, while unforeseen power cuts might cause a loss of important documents. If you have proper up-to-date backups, you can easily recover after such an incident and get back to work. It is also equally important to update backups on a regular basis so that the newest information remains intact - you can set this process to be performed automatically.
When you have the previous version of every important document or project you can avoid frustration and breakdowns. It comes in handy when malware strikes out of nowhere. Use for the data restoration process.
From our report of Feb 2021 · not reviewed since
Recommendations for the System Security Tool virus removal
Essentially, there are two ways to remove System Security Tool from the computer: automatic and manual removal.
At the end of this article, you can find the manual virus removal guide; however, this removal option is recommended only for users who have higher than average computer knowledge. Removing viruses manually not only about following instructions but also requires technical skill, because different virus components may be scattered around and hidden deep in the computer's system.
For quicker and more precise virus elimination, the security experts suggest the automatic System Security Tool removal approach. You can simply rely on professional antivirus tools to help you get rid of the virus. Just do not forget to keep the virus database updates to ensure the best protection.
Questions about System Security Tool ads
Can I safely uninstall System Security Tool?
If you did not install System Security Tool yourself and it is not part of your hardware or a program you rely on, yes. Uninstalling an unwanted program does not harm Windows.
Before you do, search the exact name and publisher to be sure it is not a driver tool, a printer utility or a game launcher with an odd name. Then remove it from Settings, Apps, Installed apps.
Ignore any offers or warnings in its uninstaller about losing protection or performance. Afterwards check Startup apps and your browsers for leftovers, and restart once to confirm that it does not reinstall itself.
System Security Tool came back after I uninstalled it. Why?
Something else is reinstalling it. Common causes are a second program from the same publisher, a scheduled task that downloads it again, or a browser extension that keeps prompting for it. Sort Installed apps by install date and uninstall each entry from the same day that you did not choose.
Then open Task Scheduler and look in the Task Scheduler Library for tasks with updater-style names that you do not recognise. Check Startup apps in Task Manager too. If System Security Tool still returns, start Windows in Safe Mode, uninstall it there and run a Microsoft Defender offline scan, which looks for loaders that ordinary scans can miss.
Can adware slow down my PC?
Yes. Adware runs in the background, loads ad scripts, opens extra tabs and contacts its servers, all of which use processor time, memory and bandwidth. Ad-heavy extensions also slow down every page, because they inspect and change it before you see it.
The effect is strongest on older PCs and when several adware programs arrived together. After removal, restart the PC and check Task Manager for anything still using a lot of resources that you do not recognise. Speed usually returns to normal once the ads stop.
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 System Security Tool?
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.
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.
Is System Security Tool a virus?
Not in the strict sense:
- System Security Tool is unwanted software
- classed here as an adware extension
- not a self-copying virus
Security programs often label such software as adware, a potentially unwanted program or a browser hijacker. It still needs removal, because it changes browser settings, shows ads and can lead you to unsafe pages. The larger risk is clicking an ad that leads to a fake update or scam page.
Will Fortect remove System Security Tool?
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 System Security Tool, 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
- Google Chrome Help: Use notifications to get alerts (no longer online) (read October 7, 2026)
- FTC: How to recognize, remove and avoid malware (read October 7, 2026)
- Microsoft Learn: Microsoft Defender Offline (read October 7, 2026)
- Microsoft Learn: How Microsoft names malware (read October 7, 2026)