Unusual Activity Scam
Written by Tomas Meskauskas on (updated)
What is Unusual activity?
Displayed by a malicious website, "The problem is caused by an unusual activity performed on this machine" is a fake pop-up error message claiming that the system is infected. Research shows that users often visit this site inadvertently - they are redirected by potentially unwanted programs (PUPs).
These rogue applications infiltrate systems without permission or trick users to install by falsely claiming to provide various "useful features". As well as causing redirects, PUPs track browsing activity and generate intrusive online advertisements.
The "Unusual activity" error states that a system virus has been detected, online privacy at risk, and the system is unable to function properly (for example, install updates, etc.) The pop-up recommends that users remove "malware" immediately and encourages them to contact "certified technicians" via a telephone number ("0161 791 9251") provided.
By calling, victims will supposedly receive help in resolving this issue. Bear in mind, however, that the message is fake - merely a scam that cyber criminals use to scare and trick victims into calling and paying for services (technical support) that are not required.
Therefore, "Unusual activity" should be ignored and can be removed simply by closing the web browser. PUPs continually monitor browsing activity by recording various data that might contain personal details.
The list of collected data types usually includes (but is not limited to) Internet Protocol (IP) addresses, website URLs visited, pages viewed, queries entered into search engines, mouse/keyboard activity, and geographic locations. PUP developers aim to generate revenue by selling the data to third parties - potentially, cyber criminals.
These criminals also have an identical purpose: to misuse personal details to generate revenue. This behavior can lead to serious privacy issues or even identity theft. Another downside is display of intrusive online ads. These generate banners, pop-ups, coupons, and other similar ads.
To achieve this, developers employ various tools (including a "virtual layer") that enables placement of third party graphical content on any site. Therefore, the ads often conceal underlying content, thereby significantly diminishing the browsing experience.
In addition, they can lead to dubious websites or even run malicious scripts that download and install malware or other PUPs. Therefore, clicking them risks further computer infections. For these reasons, uninstall all PUPs immediately.
| Name | "Unusual activity" virus |
| Threat Type | Adware, Unwanted ads, Pop-up Virus |
| Symptoms | Seeing advertisements not originating from the sites you are browsing. Intrusive pop-up ads. Decreased Internet browsing speed. |
| Distribution methods | Deceptive pop-up ads, free software installers (bundling), fake flash player installers. |
| Damage | Decreased computer performance, browser tracking - privacy issues, possible additional malware infections. |
| Malware Removal (Windows) | To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Combo Cleaner. |
There many fake errors that share similarities with "Unusual activity" including, for example, Warning! Malware Detected!, Your Computer May Have a Virus!, Unauthorized Access Detected !, and Your Windows Licence Has Expired. All claim that the system is infected, missing files, or damaged in other similar ways.
As with "Unusual activity", however, these errors are designed only to trick users into paying for services that are not required. They should never be trusted. PUPs are also very similar - most offer 'useful features', however, these claims are merely attempts to give the impression of legitimacy. The only purpose of PUPs is to generate revenue for the developers.
Rather than giving any value for regular users, they promote various websites (by causing unwanted redirects), deliver intrusive ads, and gather various data. Many of the promoted websites are fake search engines. As with PUPs, fake search engines promote suspicious websites, generate advertisements, and collect private information.
To promote other sites, these "search engines" generate fake results. As with intrusive ads, fake results often lead to malicious websites. Therefore, using a fake search engine can result in high-risk computer infections and serious privacy issues.
How did adware install on my computer?
As well as intrusive ads, PUPs are distributed side with regular (mostly free) software. This deceptive marketing method is called "bundling". Developers hide bundled programs within the "Custom" or "Advanced" settings of the download/installation processes.
Rushing these processes, skipping steps, and clicking ads exposes system to risk of various infections and compromises users' privacy.
How to avoid installation of potentially unwanted applications?
The main reasons for computer infections are poor knowledge and careless behavior. To prevent system infiltration by PUPs, be extremely careful when browsing the Internet and especially when downloading/installing software. Download your software from official sources only and (if possible) use a direct download URL, rather than third party downloaders.
Most downloaders "bundle" additional software and, therefore, using them is very risky. In addition, select the "Custom/Advanced" options, carefully analyze each download/installation step, and opt-out of all additionally-included programs. Avoid clicking any ads.
Cyber criminals design intrusive ads to appear genuine and it is virtually impossible to determine if they originate from the visited (legitimate) website.
Text presented within the pop-up in the middle of the screen:
The problem is caused by an unusual activity performed on this machine. Error code: A268D3. Call customer support number 0161 791 9251 and share this code with the agent.
Text presented within the pop-up on the lower-right corner of the screen:
Windows Detected A Potential Threat On Your Computer Windows Security Essentials was unable to remove the virus. Windows detected potential threats that might compromise your privacy or damage your computer. Error Code: 0x3453423x. Windows was unable to install definition updates. System use may be harmful as critical errors have been detected Contact Support 0161 791 9251
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:
- What is Unusual activity?
- STEP 1. Uninstall deceptive applications using Control Panel.
- STEP 2. Remove adware from Internet Explorer.
- STEP 3. Remove rogue extensions from Google Chrome.
- STEP 4. Remove potentially unwanted plug-ins from Mozilla Firefox.
- STEP 5. Remove rogue extension from Safari.
- STEP 6. Remove rogue plug-ins from Microsoft Edge.
Adware removal:
Windows 11 users:
Right-click on the Start icon, select Apps and Features. In the opened window search for the application you want to uninstall, after locating it, click on the three vertical dots and select Uninstall.
Windows 10 users:
Right-click in the lower left corner of the screen, in the Quick Access Menu select Control Panel. In the opened window choose Programs and Features.
Windows 7 users:
Click Start (Windows Logo at the bottom left corner of your desktop), choose Control Panel. Locate Programs and click Uninstall a program.
macOS (OSX) users:
Click Finder, in the opened screen select Applications. Drag the app from the Applications folder to the Trash (located in your Dock), then right click the Trash icon and select Empty Trash.
In the uninstall programs window, look for any suspicious/recently-installed applications, select these entries and click "Uninstall" or "Remove".
After uninstalling the potentially unwanted program, scan your computer for any remaining unwanted components or possible malware infections. To scan your computer, use recommended malware removal software.
Remove adware from Internet browsers:
Video showing how to remove potentially unwanted browser add-ons:
Remove malicious add-ons from Internet Explorer:
Click the "gear" icon 
(at the top right corner of Internet Explorer), select "Manage Add-ons". Look for any recently-installed suspicious browser extensions, select these entries and click "Remove".
Optional method:
If you continue to have problems with removal of the "unusual activity" virus, reset your Internet Explorer settings to default.
Windows XP users: Click Start, click Run, in the opened window type inetcpl.cpl In the opened window click the Advanced tab, then click Reset.
Windows Vista and Windows 7 users: Click the Windows logo, in the start search box type inetcpl.cpl and click enter. In the opened window click the Advanced tab, then click Reset.
Windows 8 users: Open Internet Explorer and click the gear icon. Select Internet Options.
In the opened window, select the Advanced tab.
Click the Reset button.
Confirm that you wish to reset Internet Explorer settings to default by clicking the Reset button.
Remove malicious extensions from Google Chrome:
Click the Chrome menu icon 
(at the top right corner of Google Chrome), select "More tools" and click "Extensions". Locate all recently-installed suspicious browser add-ons, select these entries and click the trash can icon.
Optional method:
If you continue to have problems with removal of the "unusual activity" virus, reset your Google Chrome browser settings. Click the Chrome menu icon (at the top right corner of Google Chrome) and select Settings. Scroll down to the bottom of the screen. Click the Advanced… link.
After scrolling to the bottom of the screen, click the Reset (Restore settings to their original defaults) button.
In the opened window, confirm that you wish to reset Google Chrome settings to default by clicking the Reset button.
Remove malicious plug-ins from Mozilla Firefox:
Click the Firefox menu 
(at the top right corner of the main window), select "Add-ons". Click "Extensions", in the opened window, remove all recently-installed suspicious browser plug-ins.
Optional method:
Computer users who have problems with "unusual activity" virus removal can reset their Mozilla Firefox settings.
Open Mozilla Firefox, at the top right corner of the main window, click the Firefox menu, in the opened menu, click Help.
Select Troubleshooting Information.
In the opened window, click the Refresh Firefox button.
In the opened window, confirm that you wish to reset Mozilla Firefox settings to default by clicking the Refresh Firefox button.
Remove malicious extensions from Safari:
Make sure your Safari browser is active, click Safari menu, and select Preferences....
In the opened window click Extensions, locate any recently installed suspicious extension, select it and click Uninstall.
Optional method:
Make sure your Safari browser is active and click on Safari menu. From the drop down menu select Clear History and Website Data...
In the opened window select all history and click the Clear History button.
Remove malicious extensions from Microsoft Edge:
Click the Edge menu icon 
(at the upper-right corner of Microsoft Edge), select "Extensions". Locate all recently-installed suspicious browser add-ons and click "Remove" below their names.
Optional method:
If you continue to have problems with removal of the "unusual activity" virus, reset your Microsoft Edge browser settings. Click the Edge menu icon (at the top right corner of Microsoft Edge) and select Settings.
In the opened settings menu select Reset settings.
Select Restore settings to their default values. In the opened window, confirm that you wish to reset Microsoft Edge settings to default by clicking the Reset button.
- If this did not help, follow these alternative instructions explaining how to reset the Microsoft Edge browser.
Summary:
Commonly, adware or potentially unwanted applications infiltrate Internet browsers through free software downloads. Note that the safest source for downloading free software is via developers' websites only. To avoid installation of adware, be very attentive when downloading and installing free software. When installing previously-downloaded free programs, choose the custom or advanced installation options – this step will reveal any potentially unwanted applications listed for installation together with your chosen free program.
Post a comment:
If you have additional information on "unusual activity" virus or it's removal please share your knowledge in the comments section below.
Outstanding!
▼ Show Discussion