Your OS High Sierra Is Infected With (3) Viruses! POP-UP Scam (Mac)

What is "Your OS High Sierra Is Infected With (3) Viruses!"?

Fake virus alert messages such as "Your OS High Sierra Is Infected With (3) Viruses!" usually appear only on untrustworthy, deceptive websites. Most users arrive at these websites unintentionally - they are redirected to them by potentially unwanted applications (PUAs).

Typically, these apps infiltrate systems without users' consent. Once installed, they cause redirects to other untrustworthy websites [similar to the one that displays the "Your OS High Sierra Is Infected With (3) Viruses!" fake message]. PUAs also deliver ads and collect data.

According to the "Your OS High Sierra Is Infected With (3) Viruses!" error, your Mac computer is infected with three viruses (this number can vary).

In this case, the message states that a 'security check' found two malware infections and one spyware/phishing program, and that immediate removal is required, otherwise you might lose your apps, photos, and other files, and put banking and other personal information at risk.

The people behind these fake messages are usually scammers who trick people into downloading (and purchasing) software, paying money for their services, and so on. At time of research, scammers were promoting the Mac Cleanup Pro application that can supposedly fix all of the issues indicated, remove viruses, and so on.

Once installed, the Mac Cleanup Pro tool will find even more issues than the "initial scan" (security check found two malware infections and one spyware/phishing program). In any case, to use this application, you will have to pay for it. We do not recommend that you purchase this app or use it.

The best solution is simply to ignore the "Your OS High Sierra Is Infected With (3) Viruses!" fake virus alert message. Close the deceptive website that displays it and do not visit it again. If you cannot close it normally, close the entire browser using Activity Monitor or simply restart your computer.

Do not restore the previously closed session, since this will opens the same deceptive website that originally displayed this fake message, or another dubious site.

Unwanted applications deliver ads and gather data. PUAs deliver banners, coupons, surveys and other similar ads that are displayed via tools that enable placement of third party graphical content on any site. These can be very annoying since, when displayed, they conceal underlying content of any visited website.

Furthermore, they often lead to untrustworthy websites or run scripts designed to download unwanted applications. These unwanted apps are often categorized as information tracking apps. PUAs collect browsing-related data such as IP addresses, keystrokes, search queries, URLs of visited websites, etc.

They also collect personal and sensitive details. Developers of these apps share the collected data with third parties (perhaps cyber criminals) who misuse it to generate revenue. Installed PUAs can thus lead to problems relating to privacy, and browsing safety. Some users might be forced having their identities stolen.

Threat Summary:

Name	"Your OS High Siera Is Infected With (3) Viruses!" virus
Threat Type	Mac malware, Mac virus
Symptoms	Your Mac became slower than normal, you see unwanted pop-up ads, you get redirected to shady websites.
Distribution methods	Deceptive pop-up ads, free software installers (bundling), fake flash player installers, torrent file downloads.
Damage	Internet browsing tracking (potential privacy issues), displaying of unwanted ads, redirects to shady websites, loss of private information.
Malware Removal (Mac)	To eliminate possible malware infections, scan your Mac with legitimate antivirus software. Our security researchers recommend using Combo Cleaner. ▼ Download Combo Cleaner for Mac To use full-featured product, you have to purchase a license for Combo Cleaner. Limited seven days free trial available. Combo Cleaner is owned and operated by Rcs Lt, the parent company of PCRisk.com read more.

Scammers use a number of fake messages - usually fake virus alerts, fake errors, and so on. All are displayed on untrustworthy websites. Examples of similar fake messages are Your Computer Was Locked, Mac OS Support Alert, Spyware Were Found On Your Mac, and Error FXX000.

These fake messages often trick people into purchasing unnecessary products or paying for services provided by scammers who claim to be 'official technicians'.

All potentially unwanted applications are very similar. Developers promote them as useful tools, however, they are used to trick people into downloading unwanted apps. Generally, PUAs provide none of the functionality promised. They generate revenue for their developers and often cause various problems.

How did potentially unwanted applications install on my computer?

Potentially unwanted apps can sometimes be downloaded from their official websites, however, most users install them through intrusive advertisements or when software developers use the so-called "bundling" method. Bundling is a deceptive marketing method used to install unwanted applications with regular software.

Users are often tricked into installing them, since information regarding their presence in set-ups is not properly disclosed. Unwanted applications are usually hidden in "Custom", "Advanced" and other similar parts of the installation processes.

Careless behaviour (skipping installation steps) often usually leads to unintentional installations of PUAs. Clicking intrusive ads without understanding the possible consequences might also cause inadvertent installations.

How to avoid installation of potentially unwanted applications?

Download software from official, trustworthy sources, and using direct links only. Avoid using third party software downloaders/installers, torrents or other similar sources. Do not finish any installation without checking the available "Advanced"/Custom" and other sections/settings.

Opt-out of any unwanted offers to install additional software, and only then finish the installation. Untrustworthy ads may seem legitimate, however, once clicked, they often redirect users to untrustworthy websites (gambling, pornography, adult dating, etc.). If you encounter these ads, check for unknown/unwanted plug-ins, add-ons, and extensions installed on your browser.

Also look for unwanted programs installed on your computer. Remove unwanted entries immediately. If your computer is already infected with PUAs, we recommend running a scan with Combo Cleaner Antivirus for macOS to automatically eliminate them.

Text presented in "Your OS High Sierra Is Infected With (3) Viruses!" scam website:

Your OS High Sierra is infected with (3) viruses!
Your OS High 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 High 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!
4 minutes and seconds 54 remaining before damage is permanent.

Appearance of "Your OS High Sierra Is Infected With (3) Viruses!" scam (GIF):

Screenshot of the installer of app (Mac Cleanup Pro) promoted by scammers:

Screenshot of the app (Mac Cleanup Pro) promoted by scammers:

Instant automatic Mac malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced IT skills. Combo Cleaner is a professional automatic malware removal tool that is recommended to get rid of Mac malware. Download it by clicking the button below:
▼ DOWNLOAD Combo Cleaner for Mac 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. Limited seven days free trial available. Combo Cleaner is owned and operated by Rcs Lt, the parent company of PCRisk.com read more.

Quick menu:

• What is "Your OS High Siera Is Infected With (3) Viruses!" virus?
• How to identify a pop-up scam?
• How do pop-up scams work?
• How to remove fake pop-ups?
• How to prevent fake pop-ups?
• What to do if you fell for a pop-up scam?

How to identify a pop-up scam?

Pop-up windows with various fake messages are a common type of lures cybercriminals use. They collect sensitive personal data, trick Internet users into calling fake tech support numbers, subscribe to useless online services, invest in shady cryptocurrency schemes, etc.

While in the majority of cases these pop-ups don't infect users' devices with malware, they can cause direct monetary loss or could result in identity theft.

Cybercriminals strive to create their rogue pop-up windows to look trustworthy, however, scams typically have the following characteristics:

• Spelling mistakes and non-professional images - Closely inspect the information displayed in a pop-up. Spelling mistakes and unprofessional images could be a sign of a scam.
• Sense of urgency - Countdown timer with a couple of minutes on it, asking you to enter your personal information or subscribe to some online service.
• Statements that you won something - If you haven't participated in a lottery, online competition, etc., and you see a pop-up window stating that you won.
• Computer or mobile device scan - A pop-up window that scans your device and informs of detected issues - is undoubtedly a scam; webpages cannot perform such actions.
• Exclusivity - Pop-up windows stating that only you are given secret access to a financial scheme that can quickly make you rich.

Example of a pop-up scam:

How do pop-up scams work?

Cybercriminals and deceptive marketers usually use various advertising networks, search engine poisoning techniques, and shady websites to generate traffic to their pop-ups. Users land on their online lures after clicking on fake download buttons, using a torrent website, or simply clicking on an Internet search engine result.

Based on users' location and device information, they are presented with a scam pop-up. Lures presented in such pop-ups range from get-rich-quick schemes to fake virus scans.

How to remove fake pop-ups?

In most cases, pop-up scams do not infect users' devices with malware. If you encountered a scam pop-up, simply closing it should be enough. In some cases scam, pop-ups may be hard to close; in such cases - close your Internet browser and restart it.

In extremely rare cases, you might need to reset your Internet browser. For this, use our instructions explaining how to reset Internet browser settings.

How to prevent fake pop-ups?

To prevent seeing pop-up scams, you should visit only reputable websites. Torrent, Crack, free online movie streaming, YouTube video download, and other websites of similar reputation commonly redirect Internet users to pop-up scams.

To minimize the risk of encountering pop-up scams, you should keep your Internet browsers up-to-date and use reputable anti-malware application. For this purpose, we recommend Combo Cleaner Antivirus for macOS.

What to do if you fell for a pop-up scam?

This depends on the type of scam that you fell for. Most commonly, pop-up scams try to trick users into sending money, giving away personal information, or giving access to one's device.

• If you sent money to scammers: You should contact your financial institution and explain that you were scammed. If informed promptly, there's a chance to get your money back.
• If you gave away your personal information: You should change your passwords and enable two-factor authentication in all online services that you use. Visit Federal Trade Commission to report identity theft and get personalized recovery steps.
• If you let scammers connect to your device: You should scan your computer with reputable anti-malware (we recommend Combo Cleaner Antivirus for macOS) - cyber criminals could have planted trojans, keyloggers, and other malware, don't use your computer until removing possible threats.
• Help other Internet users: report Internet scams to Federal Trade Commission.

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