Critical System Error: x679Qs5m POP-UP Scam (Mac)

Also Known As: "Critical System Error: x679Qs5m" virus
Type: Mac Virus
Damage level: Medium

What is Critical System Error: x679Qs5m?

"Critical System Error: x679Qs5m" is a fake error message displayed by various malicious sites. It is very similar to iPhone Has Been Locked, Your Mac Is Infected With 3 Viruses, and many others.

Research shows that most users visit these sites inadvertently - they are redirected by intrusive advertisements (delivered by other rogue websites) or potentially unwanted programs (PUPs). In most cases, potentially unwanted programs infiltrate systems without permission. As well as causing redirects, they deliver intrusive advertisements and gather sensitive information.

Critical System Error: x679Qs5m scam

This error message states that the system is infected and that users must immediately perform a full system scan by clicking the "Continue" button. Be aware, however, that "Critical System Error: x679Qs5m" is a scam - clicking "Continue" triggers download of a fake anti-virus suite. These errors typically promote applications such as Mac Ads Cleaner, Mac Adware Cleaner, etc. 

The apps provide a feature allowing users to perform a 'full system scan', however, the results are false - users are presented with hundreds of "potential threats" that must be eliminated immediately. Free versions of these PUPs are supposedly incapable of eliminating them and users are encouraged to purchase 'full versions'. This is part of the scam.

Cyber criminals generate revenue by scaring and tricking gullible users into purchasing useless software. These programs merely clear the false list. Therefore, if you have already installed a fake anti-virus/system optimization tool promoted by fake errors such as "Critical System Error: x679Qs5m", uninstall the software and certainly do not pay for any full version.

Removing fake errors is simple: close the web browser. Note that some rogue sites employ scripts that prevent users from closing browsing tabs/windows. In these cases, terminate the browser using Activity Monitor or simply reboot the system. After re-running the browser, do not restore the previous session, otherwise you will return to the malicious site/s.

Potentially unwanted programs deliver coupon, banner, pop-up, and other similar ads. To achieve this, developers employ various tools that enable placement of third party graphical content on any site. Therefore, ads often conceal underlying content, thereby significantly diminishing the browsing experience.

In addition, some lead to malicious websites and execute scripts that stealthily download and install malware. Therefore, even a single accidental click can result in high-risk computer infections. Another important issue is information tracking. Potentially unwanted programs record user-system information relating to browsing activity.

IP addresses, website URLs visited, pages viewed, search queries, and other recorded data often includes personal details that developers share with third parties (potentially, cyber criminals) who misuse it to generate revenue.

Therefore, the presence of information-tracking apps such as Critical System Error: x679Qs5m might lead to serious privacy issues or even identity theft. You are strongly advised to uninstall all potentially unwanted programs immediately.

Threat Summary:
Name "Critical System Error: x679Qs5m" 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.
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As mentioned above, "Critical System Error: x679Qs5m" shares many similarities with dozens of other fake errors. All claim that the system is infected, missing files or damaged in other similar ways, however, unlike "Critical System Error: x679Qs5m", most fake errors encourage users to call fake 'tech support' to trick them into paying for services that are not required.

Potentially unwanted programs are all very similar. By offering a wide range of "useful features", they attempt to give the impression of legitimacy, however, these apps are designed only to generate revenue for the developers.

Rather than giving any real value for regular users, PUPs cause unwanted redirects, gather sensitive information, and deliver intrusive advertisements, thereby posing a direct threat to your privacy and Internet browsing safety.

How did potentially unwanted programs install on my computer?

Research shows that, although some PUPs have official download websites, most infiltrate systems without consent, since developers promote them using the aforementioned intrusive advertisements and a deceptive marketing method called "bundling" (stealth installation of PUPs with regular software).

Developers hide "bundled" programs within various sections (typically "Custom/Advanced" settings) of the download/installation processes - they do not disclose this information properly.

Furthermore, many users rush these procedures and skip steps. In addition, they often click various advertisements without understanding the possible consequences. In doing so, they expose their systems to risk of various infections and compromise their privacy.

How to avoid installation of potentially unwanted applications?

Lack of knowledge and careless behavior are the main reasons for computer infections. Therefore, pay close attention when browsing the Internet and downloading/installing software. Bear in mind that intrusive ads typically seem legitimate, but once clicked, they redirect to dubious websites (gambling, adult dating, pornography, and so on).

If you encounter these ads, immediately eliminate all dubious applications and browser plug-ins. Furthermore, select "Custom/Advanced" settings and carefully analyze each step of the download/installation processes. Opt-out of all additionally-included programs and decline offers to download/install them.

We strongly recommend that you avoid using third party downloaders/installers, since developers monetize them by promoting PUPs.

Software should be downloaded from official sources only, using direct download links. The key to computer safety is caution. If your computer is already infected with PUPs, we recommend running a scan with Combo Cleaner Antivirus for macOS to automatically eliminate them.

Text presented in "Critical System Error: x679Qs5m" error:

Your Mac is infected with (3) critical Virus! Critical System Error: x679Qs5m (Urgent)
Your Mac (MacOS 10.13 High Sierra) system is infected with (3) virus. The pre-scan has found (2) malware and (1) phishing / spyware. Kernel Cache Damage: 28.1% - Immediate Scan is required to prevent system corruption.
May lose your hard drive content in 1 minutes and 30 seconds.

Instant automatic Mac malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced computer 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:

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:

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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About the author:

Tomas Meskauskas

Tomas Meskauskas - expert security researcher, professional malware analyst.

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for pcrisk.com since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

PCrisk security portal is brought by a company RCS LT. Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.

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Malware activity

Global malware activity level today:

Medium threat activity

Increased attack rate of infections detected within the last 24 hours.

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