If you find that the Safari, Firefox and Chrome are redirected to a suspicious web-page titled with “Your OS Sierra is infected with (3) viruses!” then most probably that your internet browser is infected by a malicious software from the adware (sometimes named ‘ad-supported’ software) category.
“Your OS Sierra is infected with 3 viruses” webpage is designed in order to force you into downloading and installing a potentially unwanted software or malware
The full text of the “Your OS Sierra is infected with 3 viruses” popup scam is:
Your OS Sierra is infected with (3) viruses! Your OS Sierra is infected with (3) viruses. Our security check found traces of 2 malware and 1 phishing/spyware. System damage: 28.1% - Immediate removal required! The immediate removal of the viruses is required to prevent further system damage, loss of Apps, Photos or other files. Traces of 1 phishing/spyware were found on your OS Sierra with. Personal and banking information are at risk. To avoid more damage click on 'Scan Now' immediately. Our deep scan will provide help immediately! 0 minutes and 00 seconds remaining before damage is permanent. Scan Now
The adware usually gets installed as a part of some free software. Do not be surprised, it happens, especially if you’re an active World Wide Web user. But this does not mean that you should reconcile with these unwanted redirects and advertisements. Perform the steps below to clean your MAC system without a wait, as the adware can be a way to hijack your machine with more dangerous malicious programs such as viruses and trojans. The steps that follow, I’ll show you how to get rid of ad supported software and thus remove “Your OS Sierra is infected with (3) viruses” popup from your MAC forever.
How to remove “Your OS Sierra is infected with (3) viruses” popup scam
There are a few methods which can be used to get rid of “Your OS Sierra is infected with (3) viruses” popup. But, not all potentially unwanted applications like this adware can be completely uninstalled utilizing only manual solutions. In many cases you are not able to remove any adware utilizing standard Apple Mac options. In order to delete “Your OS Sierra is infected with (3) viruses” popup you need complete a few manual steps and use reliable removal utilities. Most IT security professionals states that MalwareBytes tool is a right choice. The free application is able to search for and delete “Your OS Sierra is infected with (3) viruses” pop up warnings from your MAC and return your web-browser settings to defaults.
To remove “Your OS Sierra is infected with (3) viruses” popup scam, use the steps below:
- Deleting the “Your OS Sierra is infected with (3) viruses”, check the list of installed software first
- Remove “Your OS Sierra is infected with (3) viruses” pop up scam from Safari
- Remove “Your OS Sierra is infected with (3) viruses” pop up scam from Google Chrome
- Delete “Your OS Sierra is infected with (3) viruses” from Mozilla Firefox by resetting internet browser settings
- How to automatically delete “Your OS Sierra is infected with (3) viruses” pop up
- How to block “Your OS Sierra is infected with (3) viruses” pop-up scam
Manual “Your OS Sierra is infected with (3) viruses” fake alerts removal
Most common ad-supported software may be removed without any antivirus apps. The manual adware removal is few simple steps that will teach you how to get rid of the “Your OS Sierra is infected with (3) viruses” pop-up.
Deleting the “Your OS Sierra is infected with (3) viruses”, check the list of installed software first
We advise that you start the MAC system cleaning procedure by checking the list of installed software and uninstall all unknown or dubious apps. This is a very important step, as mentioned above, very often the malicious programs such as ad-supported software and hijacker infections may be bundled with free programs. Uninstall the unwanted programs can get rid of the annoying advertisements or browser redirect.
Open Finder and click “Applications”.
It will open a list of all applications installed on your MAC. Scroll through the all list, and remove any dubious and unknown programs. Right click to dubious program and choose “Move to Trash”. Another method is drag the program from the Applications folder to the Trash.
Most important, scroll through the all list, and move to trash any unknown applications. Don’t forget, choose Finder -> Empty Trash.
Remove “Your OS Sierra is infected with (3) viruses” pop up scam from Safari
The Safari reset is great if your web browser is hijacked or you have unwanted addo-ons or toolbars on your web browser, that installed by an malware.
Run Safari web browser. Next, choose Preferences from the Safari menu.
First, click the “Security” tab. Here, choose “Block pop-up windows”. It will stop some types of pop-ups.
Now, click the “Extensions” tab. Look for suspicious extensions on left panel, select it, then click the “Uninstall” button. Most important to remove all suspicious add-ons from Safari.
Once complete, check your start page and search provider settings. Click “General” tab. Make sure that the “Homepage” field contains the website you want or is empty.
Make sure that the “Search engine” setting shows your preferred search provider. In some versions of Safari, this setting is in the “Search” tab.
Remove “Your OS Sierra is infected with (3) viruses” pop up scam from Google Chrome
If you have ad-supported software problem or the Google Chrome is running slow, then reset Chrome settings can help you. In the steps below we’ll show you a solution to reset your Google Chrome settings to original settings without reinstall. This will also help to get rid of “Your OS Sierra is infected with (3) viruses” pop-up from your internet browser.
Open the Chrome menu by clicking on the button in the form of three horizontal dotes (
). It will display the drop-down menu. Select More Tools, then click Extensions.
Carefully browse through the list of installed extensions. If the list has the extension labeled with “Installed by enterprise policy” or “Installed by your administrator”, then complete the following guidance: Remove Chrome extensions installed by enterprise policy otherwise, just go to the step below.
Open the Chrome main menu again, click to “Settings” option.
Scroll down to the bottom of the page and click on the “Advanced” link. Now scroll down until the Reset settings section is visible, as shown on the image below and press the “Reset settings to their original defaults” button.
Confirm your action, click the “Reset” button.
Delete “Your OS Sierra is infected with (3) viruses” from Mozilla Firefox by resetting internet browser settings
If your Firefox browser is redirected to “Your OS Sierra is infected with (3) viruses” without your permission or an unknown search provider shows results for your search, then it may be time to perform the web browser reset. However, your saved passwords and bookmarks will not be changed, deleted or cleared.
Launch the Mozilla Firefox and click the menu button (it looks like three stacked lines) at the top right of the web-browser screen. Next, press the question-mark icon at the bottom of the drop-down menu. It will open the slide-out menu.
Select the “Troubleshooting information”. If you are unable to access the Help menu, then type “about:support” in your address bar and press Enter. It bring up the “Troubleshooting Information” page as on the image below.
Click the “Refresh Firefox” button at the top right of the Troubleshooting Information page. Select “Refresh Firefox” in the confirmation dialog box. The Mozilla Firefox will start a task to fix your problems that caused by the “Your OS Sierra is infected with (3) viruses” adware. Once, it is done, click the “Finish” button.
How to automatically delete “Your OS Sierra is infected with (3) viruses” pop up
If you’re not expert at MAC technology, then we suggest to run free removal tools listed below to get rid of “Your OS Sierra is infected with (3) viruses” pop-up for good. The automatic solution is highly recommended. It has less steps and easier to implement than the manual method. Moreover, it lower risk of system damage. So, the automatic “Your OS Sierra is infected with (3) viruses” removal is a better option.
How to remove “Your OS Sierra is infected with (3) viruses” with MalwareBytes AntiMalware (MBAM)
We suggest using the MalwareBytes Anti-Malware (MBAM) which are completely clean your MAC of the ad supported software. This free utility is an advanced malicious software removal program designed by (c) Malwarebytes lab. This application uses the world’s most popular anti-malware technology. It is able to help you remove annoying “Your OS Sierra is infected with (3) viruses” pop-up warnings from your web browsers, potentially unwanted programs, malware, browser hijacker, toolbars, ransomware and other security threats from your Apple Mac for free.
- Click the link below to download MalwareBytes Free.
Malwarebytes Anti-malware (Mac)
20841 downloads
Author: Malwarebytes
Category: Security tools
Update: September 10, 2020
- Once downloading is finished, please close all programs and open windows on your MAC OS. Run the downloaded file. Follow the prompts.
- The MalwareBytes Anti-Malware (MBAM) will open and open the main window.
- Further, click the “Scan” button to perform a system scan for the adware that causes web-browsers to display misleading “Your OS Sierra is infected with (3) viruses” popup scam. Depending on your computer, the scan can take anywhere from a few minutes to close to an hour.
- When the system scan is complete, the results are displayed in the scan report.
- Once you’ve selected what you wish to remove from your Apple Mac press the “Remove Selected Items” button.
- Close the Anti-Malware and continue with the next step.
How to block “Your OS Sierra is infected with (3) viruses” pop-up scam
The AdGuard is a very good ad-blocking application for the Safari, Chrome and Firefox, with active user support. It does a great job by removing certain types of unwanted advertisements, popunders, pop ups, unwanted newtab pages, and even full page ads and web site overlay layers. Of course, the AdGuard can stop the “Your OS Sierra is infected with (3) viruses” pop up scam automatically or by using a custom filter rule.
- Visit the following page to download the latest version of AdGuard for Mac.
AdGuard for Mac download
3677 downloads
Author: © Adguard
Category: Security tools
Update: January 17, 2018
- Once the download is finished, run the downloaded file. You will see the “Setup Wizard” program window. Follow the prompts.
- Once the setup is finished, click “Skip” to close the setup application and use the default settings, or click “Get Started” to see an quick tutorial that will help you get to know AdGuard better.
- In most cases, the default settings are enough and you don’t need to change anything. Each time, when you run your computer, AdGuard will start automatically and stop unwanted pop-up advertisements, block “Your OS Sierra is infected with (3) viruses” scam, as well as other harmful or misleading websites.
How to prevent “Your OS Sierra is infected with (3) viruses” fake alerts from getting inside your Apple Mac
The ad supported software come along with some free software. So always read carefully the setup screens, disclaimers, ‘Terms of Use’ and ‘Software license’ appearing during the install procedure. Additionally pay attention for optional applications that are being installed along with the main program. Ensure that you unchecked all of them! Also, run an adblocker application that will allow to stop malicious, misleading, illegitimate or untrustworthy web sites.
Finish words
Once you’ve finished the steps outlined above, your MAC OS should be clean from adware that causes internet browsers to show misleading “Your OS Sierra is infected with (3) viruses” pop up warnings and other malicious software. The Chrome, Safari and Mozilla Firefox will no longer redirect you to various intrusive web pages like “Your OS Sierra is infected with (3) viruses”. Unfortunately, if the step-by-step guide does not help you, then you have caught a new ad supported software, and then the best way – ask for help here.
