Home > Mac Viruses > “Your OS Sierra is infected with (3) viruses!” Scam – Remove It

“Your OS Sierra is infected with (3) viruses!” Scam – Remove It

Your OS Sierra is infected with (3) viruses! scam message loaded by lp.tweakingtools.info website

This is an article that provides details on Your OS Sierra is infected with (3) viruses! message and presents a complete set of removal steps.

”Your OS Sierra is infected with (3) viruses!”, “Your mac is infected with 3 viruses” or simply “Your system is infected with 3 viruses” is a scam message that attempts to trick you into downloading hoax cleanup software. According to its text, your Mac is infected with malware that endangers your personal and banking information. Beware that this information is misleading. However, there is still a chance that an undesired program installed on your Mac is causing the appearance of this scam message.

Threat Summary

Name Your OS Sierra is infected with (3) viruses!
Type Scam
Short Description Scam message that interrupts browsing sessions in an attempt to scare you and urge you to follow misleading steps.
Symptoms You see a message that claims your Mac has been infected with serious malware infections along with an offer to reslove the issues.
Distribution Method Bundled packages; Freeware installers
Detection Tool See If Your System Has Been Affected by malware

Combo Cleaner

Malware Removal Tool

User Experience Join Our Forum to Discuss Your OS Sierra is infected with (3) viruses!.

Your OS Sierra is infected with (3) viruses! – Spread Mechanisms

A probable reason for witnessing redirects to questionable websites that show ”Your OS Sierra is infected with (3) viruses!” scam message is the presence of an undesired program on your device. Programs of this kind often land on users devices as part of other desired applications. This spread technique is called software bundling and its main purpose is to trick you into installing additional and mostly undesired programs without noticing their presence.

For the purpose, installers of such deceptive freeware do not disclose properly all apps that are going to be installed after a click on their Finish button. Happily, sometimes you have the chance to outsmart this shady technique and prevent installing potentially undesired apps. It is usually hidden in the Advanced/Custom setup option. Once you select this way of installing your freshly downloaded app, you could be presented with more details on the presence of extra apps, choose only those you desire and then proceed further.

Your OS Sierra is infected with (3) viruses! – More About This Scam

”Your OS Sierra is infected with (3) viruses!” is one of many scam messages that are spreading across the web. All these messages present users scary “facts” about their devices in an attempt to convince them into downloading rogue programs. Once your browser loads the website that hosts ”Your OS Sierra is infected with (3) viruses!” you see the following message:

Your OS Sierra is infected with (3) viruses! scam message loaded by lp.tweakingtools.info website

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.

Currently, the domain address lp.tweakingtools.info is the one associated with this new scam message. However, there may be many more domains that are set to display the same message.

Soon after this page loads you a pop-up appears on screen to present you more false data:

second message displayed by Your OS Sierra is infected with (3) viruses! scam sensorstechforum

Text on pop-up:

We have detected a Trojan virus (e.tre456_worm_osx) on your Mac.
Press OK to begin the repair process.

We know that is sounds devastating but don’t be scared. This information along with the ineffective timer is misleading. As you may already guess that the purpose of this scam message is to urge you to click on the ”Scan Now” and resolve all malware issues that endanger your Mac. However, by doing so you could only create some issues and this time they will be for real.

It appears that the app that ”Your OS Sierra is infected with (3) viruses!” attempts to push one of those rogue clean up utilities that have exactly the opposite effect. The program is called Mac Cleaner and similar to [wplinkpreview url=”https://sensorstechforum.com/mac-auto-fixer-virus-program-remove/”]Mac Auto Fixer and [wplinkpreview url=”https://sensorstechforum.com/mac-heal-pro-fake-optimizer-remove-mac/”]Mac Heal Pro it is considered to be a fake system optimizer. Once installed such apps demand you to run a scan of your device. This scan almost always ends with the report of various types of fake errors detections in order that you will be more prone to purchase the full version of the product and resolve the issues.

In fact, this type of scam has been harassing online users for quite a long time. Our team has detected and reported a few more messages that are similar to this scam. Among them are [wplinkpreview url=”https://sensorstechforum.com/mac-might-infected-scam-redirect-virus-remove/”]”Your Mac Might Be Infected”, [wplinkpreview url=”https://sensorstechforum.com/remove-mac-os-infected-spyware-scam/”]“MAC OS is infected with Spyware” and [wplinkpreview url=”https://sensorstechforum.com/system-infected-3-viruses-e-tre456_worm_osx-mac-scam-remove/”]Your system is infected with 3 viruses!

The best you can do in case that you have detected such a scam to appear on your Mac is to focus on detecting if there are some potentially unwanted and harmful files running on your system and remove them as soon as possible. You could use the information below for the process.

Remove “Your OS Sierra is infected with (3) viruses!” Scam

In order to remove ”Your OS Sierra is infected with (3) viruses!” scam message and all files that may be causing its appearance in the browser you should complete the set of removal steps presented below. You could choose between manual and automatic removal approach but what we recommend for maximum security is their combination. The automatic approach guarantees good efficiency as after a scan with an advanced anti-virus tool you could see the exact location of all suspicious files and remove them.

In case that you have further questions or need additional help, don’t hesitate to leave a comment or contact us via email.

Gergana Ivanova

Highly motivated writer with 5+ years of experience writing for ransomware, malware, adware, PUPs, and other cybersecurity-related issues. As a writer, I strive to create content that is based on thorough technical research. I find joy in the process of creating articles that are easy to understand, informative, and useful. Follow me on Twitter (@IRGergana) for the latest in the field of computer, mobile, and online security.

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with SpyHunter for Mac
Your OS Sierra is infected with (3) viruses! may remain persistent on your system and may re-infect it. We recommend you to download SpyHunter for Mac and run free scan to remove all virus files on your Mac. This saves you hours of time and effort compared to doing the removal yourself.
Free Remover allows you, subject to a 48-hour waiting period, one remediation and removal for results found. Read EULA and Privacy Policy

Steps to Prepare Before Removal:

Before starting to follow the steps below, be advised that you should first do the following preparations:

  • Backup your files in case the worst happens.
  • Make sure to have a device with these instructions on standy.
  • Arm yourself with patience.
  • 1. Scan for Mac Malware
  • 2. Uninstall Risky Apps
  • 3. Clean Your Browsers

Step 1: Scan for and remove Your OS Sierra is infected with (3) viruses! files from your Mac

When you are facing problems on your Mac as a result of unwanted scripts and programs such as Your OS Sierra is infected with (3) viruses!, the recommended way of eliminating the threat is by using an anti-malware program. SpyHunter for Mac offers advanced security features along with other modules that will improve your Mac’s security and protect it in the future.

Click the button below below to download SpyHunter for Mac and scan for Your OS Sierra is infected with (3) viruses!:


SpyHunter for Mac

scan and remove mac virus step 1

Quick and Easy Mac Malware Video Removal Guide

Bonus Step: How to Make Your Mac Run Faster?

Mac machines maintain probably the fastest operating system out there. Still, Macs do become slow and sluggish sometimes. The video guide below examines all of the possible problems that may lead to your Mac being slower than usual as well as all of the steps that can help you to speed up your Mac.

Step 2: Uninstall Your OS Sierra is infected with (3) viruses! and remove related files and objects

Manual Removal Usually Takes Time and You Risk Damaging Your Files If Not Careful!
We Recommend To Scan Your Mac with SpyHunter for Mac
Keep in mind, that SpyHunter for Mac needs to purchased to remove the malware threats. Click on the corresponding links to check SpyHunter’s EULA and Privacy Policy

1. Hit the ⇧+⌘+U keys to open Utilities. Another way is to click on “Go” and then click “Utilities”, like the image below shows:

remove mac virus step 1

2. Find Activity Monitor and double-click it:

remove mac virus step 2

3. In the Activity Monitor look for any suspicious processes, belonging or related to Your OS Sierra is infected with (3) viruses!:

remove mac virus step 3

Tip: To quit a process completely, choose the “Force Quit” option.

remove mac virus step 4

4. Click on the "Go" button again, but this time select Applications. Another way is with the ⇧+⌘+A buttons.

5. In the Applications menu, look for any suspicious app or an app with a name, similar or identical to Your OS Sierra is infected with (3) viruses!. If you find it, right-click on the app and select “Move to Trash”.

remove mac virus step 5

6. Select Accounts, after which click on the Login Items preference. Your Mac will then show you a list of items that start automatically when you log in. Look for any suspicious apps identical or similar to Your OS Sierra is infected with (3) viruses!. Check the app you want to stop from running automatically and then select on the Minus (“-“) icon to hide it.

7. Remove any leftover files that might be related to this threat manually by following the sub-steps below:

  • Go to Finder.
  • In the search bar type the name of the app that you want to remove.
  • Above the search bar change the two drop down menus to “System Files” and “Are Included” so that you can see all of the files associated with the application you want to remove. Bear in mind that some of the files may not be related to the app so be very careful which files you delete.
  • If all of the files are related, hold the ⌘+A buttons to select them and then drive them to “Trash”.

In case you cannot remove Your OS Sierra is infected with (3) viruses! via Step 1 above:

In case you cannot find the virus files and objects in your Applications or other places we have shown above, you can manually look for them in the Libraries of your Mac. But before doing this, please read the disclaimer below:

Disclaimer! If you are about to tamper with Library files on Mac, be sure to know the name of the virus file, because if you delete the wrong file, it may cause irreversible damage to your MacOS. Continue on your own responsibility!

1. Click on "Go" and Then "Go to Folder" as shown underneath:

fix mac virus from launch agents step 1

2. Type in "/Library/LauchAgents/" and click Ok:

fix mac virus from launch agents step 2

3. Delete all of the virus files that have similar or the same name as Your OS Sierra is infected with (3) viruses!. If you believe there is no such file, do not delete anything.

fix mac virus from launch agents step 3

You can repeat the same procedure with the following other Library directories:

→ ~/Library/LaunchAgents

Tip: ~ is there on purpose, because it leads to more LaunchAgents.

Step 3: Remove Your OS Sierra is infected with (3) viruses! – related extensions from Safari / Chrome / Firefox

Remove an extension from Safari and reset it.Remove a toolbar from Google ChromeRemove a toolbar from Mozilla Firefox

1. Start Safari

2. After hovering your mouse cursor to the top of the screen, click on the Safari text to open its drop down menu.

3. From the menu, click on "Preferences"

Remove Mac virus from safari step 1

4. After that, select the 'Extensions' Tab

Remove Mac virus from safari step 2

5. Click once on the extension you want to remove.

6. Click 'Uninstall'

Remove Mac virus from safari step 3

A pop-up window will appear asking for confirmation to uninstall the extension. Select 'Uninstall' again, and the Your OS Sierra is infected with (3) viruses! will be removed.

How to Reset Safari
IMPORTANT: Before resetting Safari make sure you back up all your saved passwords within the browser in case you forget them.

Start Safari and then click on the gear leaver icon.

Click the Reset Safari button and you will reset the browser.

1. Start Google Chrome and open the drop menu

remove mac virus from google chrome step 1

2. Move the cursor over "Tools" and then from the extended menu choose "Extensions"

remove mac virus from google chrome step 2

3. From the opened "Extensions" menu locate the add-on and click on the garbage bin icon on the right of it.

remove mac virus from google chrome step 3

4. After the extension is removed, restart Google Chrome by closing it from the red "X" in the top right corner and start it again.

1. Start Mozilla Firefox. Open the menu window

2. Select the "Add-ons" icon from the menu.

remove mac virus from mozilla firefox step 1

3. Select the Extension and click "Remove"

remove mac virus from mozilla firefox step 2

4. After the extension is removed, restart Mozilla Firefox by closing it from the red "X" in the top right corner and start it again.

Your OS Sierra is infected with (3) viruses!-FAQ

What is Your OS Sierra is infected with (3) viruses! on your Mac?

The Your OS Sierra is infected with (3) viruses! threat is probably a potentially unwanted app. There is also a chance it could be related to Mac malware.

If so, such apps tend to slow your Mac down siginficantly and display advertisements. They could also use cookies and other trackers to obtain browsing information from the installed web browsers on your Mac.

The creators of such unwanted apps work with pay-per-click schemes to get your Mac to visit risky or different types of websites that may generate them funds. This is why they do not even care what types of websites show up on the ads. This makes their unwanted software indirectly risky for your MacOS.

Can Macs Get Viruses?

Yes. As much as any other device, Apple computers do get malware. Apple devices may not be a frequent target by malware authors, but rest assured that the following Apple devices can become infected with a threat:

  • iMac
  • Mac Mini
  • Macbook Air
  • Macbook Pro
  • iPhone
  • iPad

What Are The Symptoms of Your OS Sierra is infected with (3) viruses! On Mac?

There are several symptoms to look for when this particular threat and also most Mac threats in general are active:

Symptom #1: Your Mac may become slow and has poor performance in general.

Symtpom #2: You have toolbars, add-ons or extensions on your web browsers that you don't remember adding.

Symptom #3: You see all types of ads, like ad-supported search results, pop-ups and redirects to randomly appear.

Symptom #4: You see installed apps on your Mac running automatically and you do not remember installing them.

Symptom #5: You see suspicious processes running in your Mac's Activity Monitor.

If you see one or more of those symptoms, then security experts reccomend that you check your Mac for viruses.

What Types of Mac Threats Are There?

According to most malware researchers and cyber-security experts, the threats that can currently infect your Mac can be the following types:

  • Rogue Antivirus programs.
  • Adware and hijackers.
  • Trojan horses and other spyware.
  • Ransomware and screen-lockers.
  • Cryptocurrency miner malware.

What To Do If I Have a Mac Virus, Like Your OS Sierra is infected with (3) viruses!?

Do not panic! You can easily get rid of most Mac threats by firstly isolating them and then removing them. One recommended way to do that is by using a reputable malware removal software that can take care of the removal automatically for you.

There are many Mac anti-malware apps out there that you can choose from. SpyHunter for Mac is one of the reccomended Mac anti-malware apps, that can scan for free and detect any viruses. This saves time for manual removal that you would otherwise have to do.

How to Secure My Data from Your OS Sierra is infected with (3) viruses!?

With few simple actions. First and foremost, it is imperative that you follow these steps:

Step 1: Find a safe computer and connect it to another network, not the one that your Mac was infected in.

Step 2: Change all of your passwords, starting from your e-mail passwords.

Step 3: Enable two-factor authentication for protection of your important accounts.

Step 4: Call your bank to change your credit card details (secret code, etc.) if you have saved your credit card for online shopping or have done online activiites with your card.

Step 5: Make sure to call your ISP (Internet provider or carrier) and ask them to change your IP address.

Step 6: Change your Wi-Fi password.

Step 7: (Optional): Make sure to scan all of the devices connected to your network for viruses and repeat these steps for them if they are affected.

Step 8: Install anti-malware software with real-time protection on every device you have.

Step 9: Try not to download software from sites you know nothing about and stay away from low-reputation websites in general.

If you follow these reccomendations, your network and Apple devices will become significantly more safe against any threats or information invasive software and be virus free and protected in the future too.

More tips you can find on our MacOS Virus section, where you can also ask any questions and comment about your Mac problems.

About the Your OS Sierra is infected with (3) viruses! Research

The content we publish on SensorsTechForum.com, this Your OS Sierra is infected with (3) viruses! how-to removal guide included, is the outcome of extensive research, hard work and our team’s devotion to help you remove the specific macOS issue.

How did we conduct the research on Your OS Sierra is infected with (3) viruses!?

Please note that our research is based on an independent investigation. We are in contact with independent security researchers, thanks to which we receive daily updates on the latest malware definitions, including the various types of Mac threats, especially adware and potentially unwanted apps (PUAs).

Furthermore, the research behind the Your OS Sierra is infected with (3) viruses! threat is backed with VirusTotal.

To better understand the threat posed by Mac malware, please refer to the following articles which provide knowledgeable details.

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