Your System Detected Some Unusual Activity POP-UP Scam

Also Known As: "Your System Detected Some Unusual Activity" virus
Damage level: Medium

What is Your System Detected Some Unusual Activity?

There are many fake error messages that are displayed when users visit deceptive/untrustworthy websites. These include "Your System Detected Some Unusual Activity", a fake virus alert message that is displayed in text format and also plays an audio message.

Typically, people arrive at these deceptive websites unintentionally - they are redirected by potentially unwanted applications (PUAs). These apps infiltrate systems without users' direct permission, deliver intrusive ads, and record browsing-related information.

Your System Detected Some Unusual Activity scam

"Your System Detected Some Unusual Activity" is a fake virus alert designed to trick people into believing that there is unusual activity detected and the system is blocked due to the presence of a virus (or viruses).

According to the alert, the computer is blocked due to the Windows registration key being illegal, there is illegal software installed, the user is proliferating viruses over the internet, or the system has been hacked and being used from an undefined location.

Scammers behind the "Your System Detected Some Unusual Activity" fake message claim to be members of Windows Support and urge people to contact them via the +1-877-286-9666 telephone number.

They state that detected viruses (or other unusual activity) might cause damage to the computer or result in financial data tracking. The main purpose of this fake virus alert message is to trick people into contacting scammers and paying for their services or products that will supposedly solve the problems.

Note that statements about the presence of viruses on the system, possible financial data tracking activities, the computer being blocked, and so on, are false. These fake messages should never be trusted. The best solution is to simply ignore them by closing the deceptive browser window.

Note that this fake virus alert window downloads files that crash the browser, rendering it unresponsive. This can make the fake error seem even more believable. If it prevents you from closing the browser, terminate the process using Task Manager, or simply restart the computer.

In any case, do not reopen/restore the closed session, since this will return you to the same situation.

Most potentially unwanted apps that lead to deceptive websites deliver intrusive advertisements and collect browsing-related (and other) data. PUAs deploy coupons, banners, pop-ups, surveys, and so on, that are displayed using tools that enable placement of third party graphical content on any site.

Therefore, they are annoying, since they conceal underlying content of any visited website. Furthermore, when clicked, they often lead to other untrustworthy websites or even execute scripts designed to download/install other PUAs.

These apps often record data, such as IP addresses, keystrokes, URLs of visited websites, search queries, and also personal data.

Their developers share the data with third parties (potentially, cyber criminals) who misuse it to generate revenue. In summary, having unwanted apps installed leads to redirects to deceptive websites, privacy risks, browsing issues, computer infections, and even identity theft.

Threat Summary:
Name "Your System Detected Some Unusual Activity" virus
Threat Type Phishing, Scam, Social Engineering, Fraud
Cyber Criminals' Phone Number +1-877-286-9666, +1-877-635-8489
Symptoms Unauthorized online purchases, changed online account passwords, identity theft, illegal access of one's computer.
Distribution methods Deceptive emails, rogue online pop-up ads, search engine poisoning techniques, misspelled domains.
Damage Loss of sensitive private information, monetary loss, identity theft.
Malware Removal (Windows)

To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Combo Cleaner.
▼ Download Combo Cleaner
To use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by Rcs Lt, the parent company of PCRisk.com read more.

Some other examples of fake messages are This Computer Is Blocked, MS MALWARE ALERT and Your Computer Was Locked. Most of these fake messages are very similar.

Typically, scammers use them to trick people into purchasing products or services that, according to them, remove viruses, fix computer problems, and so on.

PUAs share an identical purpose: to generate revenue for their developers by gathering data, causing unwanted redirects, and feeding users with intrusive ads.

How did potentially unwanted applications install on my computer?

In some cases, unwanted apps can be downloaded from their official websites, however, most people install them unintentionally by clicking intrusive advertisements or together with other software.

Frequently, users are tricked into installing unwanted apps when software developers use "bundling", a deceptive marketing method used to trick users into installing PUAs by hiding them in "Custom", "Advanced" and other similar settings.

Generally, information about the inclusion of unwanted apps within the installation/download set-ups is not properly disclosed, however, these inadvertent installations/downloads are achieved only when users skip installation/download steps and leave the available settings unchanged.

In this way, users give permission to install/download PUAs.

How to avoid installation of potentially unwanted applications?

Do not use third party software downloaders, installers, or other similar sources to download apps - use official and trustworthy sources/websites, and direct links. Never skip installation/download steps, check "Custom"/"Advanced" settings and deselect offers to install additional software/applications.

Avoid clicking intrusive ads, especially when visiting dubious/untrustworthy websites. If you are redirected to untrustworthy websites (such as pornography, adult dating, gambling, and so on), check installed extensions, plug-ins, and add-ons on your browser and remove all suspicious entries.

Also remove unwanted programs from your operating system. If your computer is already infected with PUAs, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate them.

Text presented in "Your System Detected Some Unusual Activity" pop-up:

This computer is BLOCKED
Do not close this windows and restart your computer
Your computer's registration key is Blocked.
Why we blocked your computer?
The window's registration key is illegal.
This window is using pirated software.
this window is sending virus over the Internet.
This window is hacked or used from undefined location.
We block this computer for your security
Contact microsoft helpline to reactivate your computer.

The appearance of "Your System Detected Some Unusual Activity" pop-up (GIF):

Your System Detected Some Unusual Activity scam gif

Text presented in "Your System Detected Some Unusual Activity" website's background: 

Windows Support Alert
Your System Detected Some Unusual Activity
It might harm your computer data and track your financial activities
Please report this activity to +1-877-286-9666
[Ignore Alert] [Chat Now]

Another variant of "Your System Detected Some Unusual Activity" pop-up scam:

Your System Detected Some Unusual Activity pop-up scam (2021-03-26)

Text presented within this pop-up:

Why we blocked your computer?

Your System Detected Some Unusual Activity.

Call Helpline 1-877-635-8489 (Toll Free)

[Quick Helpline] [Go Back Safety]

Instant automatic 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 malware. Download it by clicking the button below:
▼ DOWNLOAD Combo Cleaner 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. 7 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 Windows.

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 Windows) - 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.

▼ Show Discussion

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.

Our malware removal guides are free. However, if you want to support us you can send us a donation.

About PCrisk

PCrisk is a cyber security portal, informing Internet users about the latest digital threats. Our content is provided by security experts and professional malware researchers. Read more about us.

Removal Instructions in other languages
Malware activity

Global malware activity level today:

Medium threat activity

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

QR Code
Your System Detected Some Unusual Activity virus QR code
Scan this QR code to have an easy access removal guide of "Your System Detected Some Unusual Activity" virus on your mobile device.
We Recommend:

Get rid of Windows malware infections today:

Download Combo Cleaner

Platform: Windows

Editors' Rating for Combo Cleaner:
Editors ratingOutstanding!

[Back to Top]

To use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by Rcs Lt, the parent company of PCRisk.com read more.