CumulusCongestus Malicious Extension – Virus Removal Guide

CumulusCongestus is a browser extension that injects advertisements into websites you visit and redirects your browser search queries. CumulusCongestus uses the “Managed by your organization” policy to prevent users from easily removing it. 

CumulusCongestus

What is the CumulusCongestus extension?

CumulusCongestus is a malicious browser hijacker designed to inject advertisements and redirect searches without consent. Once installed, CumulusCongestus can be difficult to uninstall due to its “Managed by your organization” policy that prevents easy removal.

When your browser is infected with the CumulusCongestus hijacker, you may notice unwanted ads on websites, links redirecting to unfamiliar sites, and your search engine queries going through shady third-party engines rather than your preferred search engine.

The CumulusCongestus browser hijacker works by infecting web browsers like Google Chrome, Mozilla Firefox, Microsoft Edge, and Apple Safari. After infection, CumulusCongestus can:

  • Inject advertisements into websites you visit, displaying ads that don’t originate from the actual site.
  • Redirect your web searches through unwanted affiliate marketing search engines that generate revenue for the hijacker creators.
  • Change website links to redirect your browser to unfamiliar and potentially dangerous sites.
  • Makes it difficult to remove due to its “Managed by your organization” policy that requires advanced tech skills to remove.

How was the CumulusCongestus extension installed on my computer?

The CumulusCongestus extension is installed by the users, whether that is knowingly or not. Often, this type of program is offered through malicious advertisements, leaving the user puzzled about where this software came from.

The CumulusCongestus extension is being promoted through ads similar to the one shown below.

Image: Malicious advertisement distributing Ad Avenger extension
Image: Malicious advertisement distributing CumulusCongestus extension

Less than reputable sites can redirect your browser to these CumulusCongestus ads to generate advertising revenue. If this happens, you can close the page and install a legitimate ad blocker like AdGuard to remove ads from the sites you visit.
However, if you continuously see these CumulusCongestus ads, then your computer might be infected with a malicious program, and we will need to scan your device for malware and remove it.

If you do not know how the CumulusCongestus extension was installed or are concerned other extensions or unwanted programs may be installed on your device, you can use the removal guide below.

Removal Instructions for CumulusCongestus Extension

This malware removal guide may appear overwhelming due to the number of steps and numerous programs that are being used. We have only written it this way to provide clear, detailed, and easy-to-understand instructions that anyone can use to remove malware for free.
Please perform all the steps in the correct order. If you have any questions or doubts at any point, stop and ask for our assistance.
Browser hijackers and adware can infect Windows and Mac devices, so we’ve covered below both operating systems. Depending on which operating system is installed on the device is the CumulusCongestus extension, please click on the operating system icon below and follow the displayed steps to remove it.
Removal Instructions for Windows

Remove CumulusCongestus from Windows

To remove the CumulusCongestus extension from your computer, follow these steps:

STEP 1: Use Rkill to terminate malicious processes

In this first step, we will download and run Rkill to terminate malicious processes that may be running on your computer.

RKill is a program that was developed at BleepingComputer.com that attempts to terminate known malware processes so that your normal security software can then run and clean your computer of infections. When RKill runs it will kill malware processes and then removes incorrect executable associations and fixes policies that stop us from using certain tools.

  1. Download Rkill.

    You can download RKill to your computer from the below link. When at the download page, click on the Download Now button labeled iExplore.exe. We are downloading a renamed version of Rkill (iExplore.exe) because some malware will not allow processes to run unless they have a certain filename.

    RKILL DOWNLOAD LINK

    (The above link will open a new page from where you can download Rkill)
  2. Run RKill.

    After downloading, double-click the iExplore.exe icon to kill malicious processes. In most cases, downloaded files are saved to the Downloads folder.
    The program may take some time to search for and end various malware programs.

    RKILL Window

    When it is finished, the black window will close automatically and a log file will open. Do not restart your computer. Proceed to the next step in this guide.

STEP 2: Uninstall malicious programs from your computer

In this second step, we will manually check if any unknown or malicious programs are installed on the computer. Sometimes adware and browser hijackers can have a usable Uninstall entry that can be used to remove them.

Windows 11Windows 10Windows 8Windows 7
  1. Press the Windows key + I on your keyboard to open the Settings app.

    First, open Windows Settings by pressing Windows+I on your keyboard. You can also right-click your Start button and select “Settings” from the list.
    Windows 11 Open Settings

  2. In the Settings app, click on “Apps” and then “Apps & features”.

    When Settings opens, click “Apps” in the sidebar, then select “Apps & Features”.

    Windows 11 Apps and Feature

  3. Find the malicious program in the list of installed apps and uninstall it.

    In Apps & Features settings, scroll down to the app list and search for unknown or suspicious programs. To make things easier, you can sort all installed programs by their installation date. To do this, click “Sort by” and select “Install date”.
    Look out for any suspicious program that could be behind all the drama – anything you don’t remember downloading or that doesn’t sound like a genuine program. When you find a malicious program, click the three dots button beside it and select “Uninstall” in the menu that appears.

    Windows 11 Uninstall malicious program

    If you have checked your computer for malicious programs and did not find any, you can proceed with the next step in this guide.
  4. Follow the prompts to uninstall the program.

    In the next message box, confirm the uninstall process by clicking on Uninstall, then follow the prompts to uninstall the malicious program.
    Make sure to read all of the prompts carefully, because some malicious programs try to sneak things in hoping that you won’t read them closely.

    Windows 11 Confirm Uninstall

  1. Press the Windows key + I on your keyboard to open the Settings app.

    Press the Windows key + I on your keyboard to open the Settings app. You can also ope the Settings app by clicking the Start button on the taskbar, then select “Settings” (gear icon).
    Windows 10: Click the Start button then click on Settings

  2. In the Settings app, click on “Apps”.

    When the “Windows Settings” window opens, click on “Apps“. By default, it should open “Apps and Features” but if it doesn’t, select it from the list on the left.

    Windows 10: Click on Apps

  3. Find the malicious program in the list of installed apps and uninstall it.

    In Apps & Features settings, scroll down to the app list and search for unknown or suspicious programs. To make things easier, you can sort all installed programs by their installation date. To do this, click “Sort by” and select “Install date”.
    Look out for any suspicious program that could be behind all the drama – anything you don’t remember downloading or that doesn’t sound like a genuine program. When you find a malicious program, click on it and select “Uninstall” in the menu that appears.

    Windows 10: Uninstall malware from Windows

    If you have checked your computer for malicious programs and did not find any, you can proceed with the next step in this guide.
  4. Follow the prompts to uninstall the program.

    In the next message box, confirm the uninstall process by clicking on Uninstall, then follow the prompts to uninstall the malicious program.
    Make sure to read all of the prompts carefully, because some malicious programs try to sneak things in hoping that you won’t read closely.
    Windows 10: Complete the uninstall process

  1. Go to “Program and Features”.

    Right-click on the Start button in the taskbar, then select “Programs and Features”. This will take you directly to your list of installed programs.
    Right click on Start and select Programs and Features

  2. Search for malicious program and uninstall it.

    The “Programs and Features” screen will be displayed with a list of all the programs installed on your computer. Scroll through the list until you find any unknown or suspicious program, then click to highlight it, then click the “Uninstall” button.

    Look out for any suspicious program that could be behind all the drama – anything you don’t remember downloading or that doesn’t sound like a genuine program.

    If you have checked your computer for malicious programs and did not find any, you can proceed with the next step in this guide.

    Select malicious program then click on Uninstall

  3. Follow the on-screen prompts to uninstall malicious program.

    In the next message box, confirm the uninstall process by clicking on Yes, then follow the prompts to uninstall malicious program. Make sure to read all of the prompts carefully, because some malicious programs try to sneak things in hoping that you won’t read closely.

  1. Open the “Control Panel”.

    Click on the “Start” button, then click on “Control Panel“.
    Windows 7 go to Control Panel

  2. Click on “Uninstall a Program”.

    When the “Control Panel” appears, click on “Uninstall a Program” from the Programs category.
    Select Uninstall malicious program from Control Panel

  3. Search for malicious programs and uninstall them.

    The “Programs and Features” screen will be displayed with a list of all the programs installed on your computer. Scroll through the list until you find any suspicious or unknown program, then click to highlight it, then click the “Uninstall” button.
    Look out for any suspicious program that could be behind all the drama – anything you don’t remember downloading or that doesn’t sound like a genuine program.

    If you have checked your computer for malicious programs and did not find any, you can proceed with the next step in this guide.

    Uninstall malware from Windows 7

  4. Follow the on-screen prompts to uninstall malicious program.

    In the next message box, confirm the uninstall process by clicking on Yes, then follow the prompts to uninstall malicious program. Make sure to read all of the prompts carefully, because some malicious programs try to sneak things in hoping that you won’t read closely.

If you are experiencing difficulty while attempting to uninstall a program, you can use Revo Uninstaller to completely remove the unwanted program from your computer.

Now that the malicious programs have been removed from your computer, we can proceed with the next step in this guide.

STEP 3: Remove malicious browser policies from Windows

In this third step, we will download the Chrome Policy Remover file (credits to Stefan Van Damme) and remove the malicious browser policies. .


  1. Download the Chrome Policy Remover.


    Download the “Chrome Policy Remover for Windows” file from the below link. This file is a batch script designed to automatically remove Chrome policies.

    CHROME POLICY REMOVER DOWNLOAD LINK
    (The above link will download delete_chrome_policies on your computer.)

    Note: Windows might display a security warning because the file is a batch script (.bat). This is a standard security measure. Since the Chrome Policy Remover is a trusted tool, clicking “Keep” allows you to proceed with the download.

  2. Right-click “delete_chrome_policies.bat” file and select Run as administrator

    We will now run the “delete_chrome_policies.bat” fiel as administrator.Running the delete_chrome_policies file as administrator grants it the necessary permissions to modify system settings related to Chrome policies. This ensures the tool can effectively remove the policies.

    BAT1
  3. Click Yes/Run at the confirmation prompt and allow the process to complete.

    Windows will ask for confirmation before allowing the script to make changes. Clicking “Yes” or “Run” (depending on your Windows version confirms your intent to run the tool and remove the Chrome policies. The script will then run and automatically remove the policies, after which you can close the command prompt window.


    BAT2

Now that the malicious policies were removed, in the next step, we will reset your browser settings to their defaults.

STEP 4: Remove malicious files and folders from Windows

In this fourth step, we will manually search and remove malicious scheduled tasks and folders on your computer.

1. Delete malicious scheduled tasks.

This infection may create a malicious scheduled task in the Task Scheduler to ensure that it is automatically reinstalled every 5 minutes after it has been deleted. This task may run at regular intervals to ensure that the infection persists on your system.

  1. Search for “Task Scheduler” in the windows search as shown below.Search for Task Scheduler.

    You can also open the Task Scheduler app by pressing the Windows + R buttons and then type “taskschd.msc” and press Enter.
  2. In the Task Scheduler window, navigate to the Task Scheduler Library on the left side of the screen.Click on Task Scheduler Library
  3. Locate the malicious scheduled task in the list of tasks. It may have a randomly generated name (eg. Chrome_Policy, Chrome_Bookmarks, Chrome_Folder) or may be identified as a suspicious or unknown task. Right-click on the malicious task and select “Delete” from the menu.Find the malicious task and delete it

2. Delete malicious files located in AppData\Roaming folder

We will now delete the malicious file that is located in the AppData\Roaming folder.

  1. Search for “Run” in the windows search as shown below, or press the Windows + R button to open the Run app.Open Run app
  2. In the run app text box, enter “%AppData%” and click OK. Windows will directly open up the Roaming folder which is inside the AppData folder.
    Roaming folder
  3. In the AppData\Roaming folder, search and delete any unknown folders with names like Default, Chrome32, Energy, Bloom, and Travel (note that the actual name on your computer may be different, but you should look for programs with similar naming conventions).Roaming Folder Malicious File

3. Delete malicious files located in AppData\Local folder

Next, we will delete the malicious folders that are located in the AppData\Local folder and the malicious Chrome browser extensions.

  1. Search for “Run” in the windows search as shown below, or press the Windows + R button to open the Run app.Open Run app
  2. In the run app text box, enter “%localappdata%” and click OK. Windows will directly open up the AppData\Local folder which is inside the AppData folder.
    Local Folder
  3. In the AppData\Local directory, search and delete the Default, WindowsApp and ServiceApp folders.

    Next, find the Google folder and go to Google > Chrome > User Data > Default (or Profile) > Extensions. Find the malicious extension folder within the Extensions folder and delete it. It may have a randomly generated name or may be identified as a suspicious or unknown extension.

    Delete chrome extensions

4. Remove Chrome Shortcut Modification

This malware can hijack your browser shortcuts to target the malicious files. Here is a short guide on how to remove the Chrome shortcut modification:

  1. Right-click on the Google Chrome shortcut on your desktop or Start Menu and select “Properties“. Open Chrome Properties
  2. Under the Shortcut tab, look for the “Target” field. This is where any added commands to the shortcut will be. Carefully examine the target path and remove any suspicious looking text that may have been appended, especially anything referencing the AppData folder.
    For example, remove text like “–load-extension=C:\Users%USERNAME%\AppData\Local\Default”.
    The target should point only to the chrome.exe file location, nothing more. Remove Malicious Chrome Shortcut Hijack
  3. Click OK to save the changes and close Properties.
  4. Launch Chrome again normally through the shortcut. The extension should no longer load on start up.

You can also right click the shortcut and select “Open File Location” to open the chrome.exe folder. Drag chrome.exe directly to your taskbar to create a clean shortcut.

Now that we have manually removed the malicious tasks and folders from your computer and cleaned your browser shortcuts, we can continue with the next step.

STEP 5: Reset your browser settings to their defaults

In this step, we will remove spam notifications,  malicious extensions, and change to default any settings that might have been changed by malware.
Please note that this method will remove all extensions, toolbars, and other customizations but will leave your bookmarks and favorites intact. For each browser that you have installed on your computer, please click on the browsers tab below and follow the displayed steps to reset that browser.

ChromeFirefoxMicrosoft EdgeInternet Explorer
Reset Chrome for Windows to default settings

We will now reset your Chrome browser settings to their original defaults. This will reset your startup page, new tab page, search engine, and pinned tabs. It will also disable all extensions and clear temporary data like cookies. Your favorites, history, and saved passwords will not be cleared.

  1. Click the three dots in the top-right corner and then click on “Settings”.

    Open Chrome and click on the menu button (represented by three vertical dots) in the top right corner of the window. In the dropdown menu that opens, click “Settings“. Click on the Chrome menu button then on the Settings button
  2. Click “Advanced”.

    Chrome’s “Settings” should now be displayed in a new tab or window, depending on your configuration. In the left sidebar, click on the “Advanced” link. Click on the Advanced link
  3. Click “Reset and clean up”.

    In the left sidebar, under the “Advanced” section, click on “Reset and clean up“. Click Reset and clean up button
  4. Click “Reset settings to their original defaults”.

    In the main window, the “Reset and clean up” section is visible, as shown in the screenshot below. Click on “Reset settings to their original defaults“. Click on Reset settings to their original defaults
  5. Click “Reset settings”.

    A confirmation dialog will now be displayed, detailing the components that will be restored to their default state should you continue with the reset process. To complete the restoration process, click on the “Reset settings” button. Click on Reset Settings to restore Google Chrome to its default settings
  6. (Optional) Reset Chrome Data Sync.

    In case a malicious extension reinstalls itself even after performing a browser reset, you have an additional option to reset the data sync for your browser. To do this, navigate to chrome.google.com/sync and click on the Clear Data button. Chrome Sync Reset
Reset Firefox for Windows to default settings

We will now reset your Firefox browser settings to their default. The reset feature fixes many issues by restoring Firefox to its factory default state while saving your essential information like bookmarks, passwords, web form auto-fill information, browsing history, and open tabs.

  1. Click the three horizontal lines in the top-right corner and then click on “Help”.

    Click on Firefox’s main menu button, represented by three horizontal lines. When the drop-down menu appears, select the option labeled “Help“.
    Click on the Firefox Menu button then select Help button

  2. Click “More troubleshooting information”.

    From the Help menu, click on “More troubleshooting information“.
    Click More Troubleshooting Information

  3. Click on “Refresh Firefox”

    When the “Troubleshooting Information” page opens, click on the “Refresh Firefox” button.
    Click on Refresh Firefox

  4. Confirm that you want to reset your browser settings.

    To finish the reset process, click on the “Refresh Firefox” button in the new confirmation window that opens.
    Click again on Refresh Firefox button

  5. Click “Finish”.

    Firefox will now close itself and will revert to its default settings. When it’s done, a window will list the information that was imported. Click on “Finish“.

    Your old Firefox profile will be placed on your desktop in a folder named “Old Firefox Data“. If the reset didn’t fix your problem you can restore some of the information not saved by copying files to the new profile that was created. If you don’t need this folder any longer, you should delete it as it contains sensitive information.

Reset Microsoft Edge to default settings

We will now reset your Microsoft Edge browser settings to their default. This will reset your startup page, new tab page, search engine, and pinned tabs. It will also disable all extensions and clear temporary data like cookies. Your favorites, history, and saved passwords will not be cleared.

  1. Click the three dots in the top-right corner and then click on “Settings”.

    In the top right corner, click on Microsoft Edge’s main menu button, represented by three horizontal dots. When the drop-down menu appears, click on “Settings“.
    Click the three dots in the top-right corner and then click on Settings

  2. Click on “Reset Settings”.

    On the left side of the window, click on “Reset Settings“.
    Click Reset Settings option

  3. Click on “Restore settings to their default values”.

    In the main window, click on “Restore settings to their default values“.
    Select Restore settings to their default values

  4. Click “Reset”.

    A confirmation dialog should now be displayed, detailing the components that will be restored to their default state should you continue with the reset process. To complete the restoration process, click on the “Reset” button.
    Click Reset to reset your browser
    Microsoft Edge will now erase all your personal data, browsing history, and disable all installed extensions. Your bookmarks, though, will remain intact and still be accessible.

Reset Internet Explorer to default settings

We will now reset your Internet Explorer browser settings to their default. You can reset Internet Explorer settings to return them to the state they were in when Internet Explorer was first installed on your computer.

  1. Go to “Internet Options”.

    Open Internet Explorer, click on the gear icon in the upper-right part of your browser, then select “Internet Options“.

  2. Select the “Advanced” tab, then click “Reset”

    In the “Internet Options” dialog box, select the “Advanced” tab, then click on the “Reset” button.

  3. Click on “Reset”.

    In the “Reset Internet Explorer settings” section, select the “Delete personal settings” checkbox, then click on the “Reset” button.

  4. Click on “Close”.

    When Internet Explorer has completed its task, click on the “Close” button in the confirmation dialogue box.
    Close your browser and then you can open Internet Explorer again.

STEP 6: Use Malwarebytes to remove trojans and browser hijackers

In this step, we will install and run a scan with Malwarebytes Free to remove any infections, adware, or potentially unwanted programs that may be present on your computer.

Malwarebytes stands out as one of the leading and widely-used anti-malware solutions for Windows, and for good reason. It effectively eradicates various types of malware that other programs often overlook, all at no cost to you. When it comes to disinfecting an infected device, Malwarebytes has consistently been a free and indispensable tool in the battle against malware. We highly recommend it for maintaining a clean and secure system.

  1. Download Malwarebytes for Windows

    You can download Malwarebytes by clicking the link below.

    MALWAREBYTES FOR WINDOWS DOWNLOAD LINK
    (The above link will open a new page from where you can download Malwarebytes)
  2.  

    Install Malwarebytes

    After the download is complete, locate the MBSetup file, typically found in your Downloads folder. Double-click on the MBSetup file to begin the installation of Malwarebytes on your computer. If a User Account Control pop-up appears, click “Yes” to continue the Malwarebytes installation.

    MBAM1
  3. Follow the On-Screen Prompts to Install Malwarebytes

    When the Malwarebytes installation begins, the setup wizard will guide you through the process.

    • You’ll first be prompted to choose the type of computer you’re installing the program on—select either “Personal Computer” or “Work Computer” as appropriate, then click on Next.

      MBAM3 1
    • Malwarebytes will now begin the installation process on your device.

      MBAM4
    • When the Malwarebytes installation is complete, the program will automatically open to the “Welcome to Malwarebytes” screen.

      MBAM6 1
    • On the final screen, simply click on the Open Malwarebytes option to start the program.

      MBAM5 1
  4. Enable “Rootkit scanning”.

    Malwarebytes Anti-Malware will now start, and you will see the main screen as shown below. To maximize Malwarebytes’ ability to detect malware and unwanted programs, we need to enable rootkit scanning. Click on the “Settings” gear icon located on the left of the screen to access the general settings section.

    MBAM8

    In the settings menu, enable the “Scan for rootkits” option by clicking the toggle switch until it turns blue.

    MBAM9

    Now that you have enabled rootkit scanning, click on the “Dashboard” button in the left pane to get back to the main screen.

  5. Perform a Scan with Malwarebytes.

    To start a scan, click the Scan button. Malwarebytes will automatically update its antivirus database and begin scanning your computer for malicious programs.

    MBAM10
  6. Wait for the Malwarebytes scan to complete.

    Malwarebytes will now scan your computer for browser hijackers and other malicious programs. This process can take a few minutes, so we suggest you do something else and periodically check the status of the scan to see when it is finished.

    MBAM11
  7. Quarantine detected malware

    Once the Malwarebytes scan is complete, it will display a list of detected malware, adware, and potentially unwanted programs. To effectively remove these threats, click the “Quarantine” button.

    MBAM12

    Malwarebytes will now delete all of the files and registry keys and add them to the program’s quarantine.

    MBAM13

  8. Restart your computer.

    When removing files, Malwarebytes may require a reboot to fully eliminate some threats. If you see a message indicating that a reboot is needed, please allow it. Once your computer has restarted and you are logged back in, you can continue with the remaining steps.

    MBAM14

STEP 7: Use HitmanPro to scan your computer for rootkits and other malware

In this next step, we will scan the computer with HitmanPro to ensure that no other malicious programs are installed on your device.

HitmanPro is a second-opinion scanner that takes a unique cloud-based approach to malware scanning. HitmanPro scans the behavior of active files and also files in locations where malware normally resides for suspicious activity. If it finds a suspicious file that’s not already known, HitmanPro sends it to its clouds to be scanned by two of the best antivirus engines today, which are Bitdefender and Kaspersky.

Although HitmanPro is shareware and costs $24.95 for 1 year on 1 PC, there is no limit on scanning. The limitation only kicks in when there is a need to remove or quarantine detected malware by HitmanPro on your system and by then, you can activate the one-time 30-days trial to enable the cleanup.

  1. Download HitmanPro.

    You can download HitmanPro by clicking the link below.

    HITMANPRO DOWNLOAD LINK
    (The above link will open a new web page from where you can download HitmanPro)
  2. Install HitmanPro.

    When HitmanPro has finished downloading, double-click on “hitmanpro.exe” (for 32-bit versions of Windows) or “hitmanpro_x64.exe” (for 64-bit versions of Windows) to install this program on your computer. In most cases, downloaded files are saved to the Downloads folder.

    Double-click on the HitmanPro file

    You may be presented with a User Account Control pop-up asking if you want to allow HitmanPro to make changes to your device. If this happens, you should click “Yes” to continue with the installation.

    Windows asking for permissions to run the HitmanPro setup

  3. Follow the on-screen prompts.

    When HitmanPro starts you will be presented with the start screen as shown below. Click on the “Next” button to perform a system scan.

    Click Next to install HitmanPro on your PC

    HitmanPro final installer screen

  4. Wait for the HitmanPro scan to complete.

    HitmanPro will now begin to scan your computer for malicious programs.
    HitmanPro scans your computer for any infections, adware, or potentially unwanted programs that may be present

  5. Click on “Next”.

    When HitmanPro has finished the scan, it will display a list of all the malware that it has found. Click on the “Next” button to have HitmanPro remove the detected items.

    HitmanPro scan summary. Click Next to remove malware

  6. Click on “Activate free license”.

    HitmanPro may now require to activate the free 30-days trial to remove the malicious files. To do this, click on the “Activate free license” button to begin the free 30 days trial and remove all the malicious files from your computer.
    Click on the Activate free license button

    When the malware removal process is complete, it will display a screen that shows the status of the various programs that were removed. At this screen, you should click on the Next button and then if prompted you should click on the Reboot button. If HitmanPro does not prompt you to reboot, please just click on the Close button.

STEP 8: Use AdwCleaner to remove adware and malicious browser policies

In this final step, we will download and install AdwCleaner to remove the malicious browser policies that were set by browser hijackers on your computer and delete malicious browser extensions.

AdwCleaner is a free popular on-demand scanner that can detect and remove malware that even the most well-known anti-virus and anti-malware applications fail to find. This on-demand scanner includes a lot of tools that can be used to fix the side effects of adware. browser hijackers and other malware.

  1. Download AdwCleaner.

    You can download AdwCleaner by clicking the link below.

    ADWCLEANER DOWNLOAD LINK

    (The above link will open a new web page from where you can download AdwCleaner)
  2. Double-click on the setup file.

    Double-click on the file named “adwcleaner_x.x.x.exe” to start AdwCleaner. In most cases, downloaded files are saved to the Downloads folder.
    Download AdwCleaner on your computer

    AdwCleaner program will now open and you will be presented with the program’s license agreement. After you read it, click on the I agree button if you wish to continue. If Windows prompts you as to whether or not you wish to run AdwCleaner, please allow it to run.

    Windows ask if you want to run AdwCleaner

  3. Enable “Reset Chrome policies” to remove malicious browser policies.

    When AdwCleaner starts, on the left side of the window, click on “Settings” and then enable “Reset Chrome policies“.

    Enable Reset Chrome policies to remove malicious browser policies

  4. Click on the “Scan” button.

    On the left side of the AdwCleaner window, click on “Dashboard” and then click “Scan” to perform a computer scan.

    Click on Scan to start a AdwCleaner scan

  5. Wait for the AdwCleaner scan to finish.

    AdwCleaner will now scan your computer for malware. This process can take a few minutes.

    AdwCleaner scanning for adware and other malware

  6. Click on “Quarantine” to remove malware.

    When the AdwCleaner scan is completed it will display all of the items it has found. Click on the “Quarantine” button to remove the malicious programs from your computer.

    Click on Quarantine to remove malware

  7. Click on “Continue” to remove the malicious programs.

    AdwCleaner will now prompt you to save any open files or data as the program will need to close any open programs before it starts to clean. Click on the “Continue” button to finish the removal process.
    Click Continue to remove malicious files

    AdwCleaner will now delete all detected malware from your computer. When the malware removal process is complete, you may be asked to restart your computer.

Your computer should now be free of the CumulusCongestus extension and other malware.

If your current antivirus allowed this malicious program on your computer, you may want to consider purchasing Malwarebytes Premium to protect against these types of threats in the future.
If you are still having problems with your computer after completing these instructions, then please follow one of the steps:

Removal Instructions for Mac

Remove CumulusCongestus from Mac

To remove the CumulusCongestus extension from your Mac, follow these steps:

STEP 1: Reset browsers back to default settings

In this first step, we will restore your browser settings back to their default configuration to remove spam
push notifications, malicious extensions, and unwanted browser settings.
Please note that this method will remove all extensions, toolbars, and other customizations but will leave your bookmarks and favorites intact. For each browser that you have installed on your computer, please click on the browsers tab below and follow the displayed steps to reset that browser.

Safari BrowserChrome for Mac BrowserFirefox for Mac Browser
Remove Malware and Spam Push Notifications from Safari

To remove spam push notifications from Safari we will check if there are any malicious extensions installed on your browser and restore your browser settings to default.

  1. Go to Safari’s “Preferences”.

    On the menu bar, click the “Safari” menu and select “Preferences”.
    On the Menu bar Click on Safari then Preference

  2. Check Homepage.

    This will open a new window with your Safari preferences, opened to the “General” tab. Some browser hijackers may change your default homepage, so in the Homepage field make sure it’s a web page you want to use as your start-up page.

    Change Homepage in Safari

  3. Click “Extensions”

    Next, click on the “Extensions” tab.
    Click on Extensions MacOS

  4. Find and uninstall malicious extensions.

    The “Extensions” screen will be displayed with a list of all the extensions installed on Safari. Look out for any suspicious browser extension that could be behind all the drama – anything you don’t remember downloading or that doesn’t sound like a genuine extension. By default, there are no extensions installed on Safari so it’s safe to remove an extension
    Click on Uninstall to remove malicious extension

  5. Remove spam notifications ads

    Click Preferences, click Websites, then click Notifications. Deselect “Allow websites to ask for permission to send push notifications”.

    Deselect Allow websites to ask for permission to send push notifications

  6. Remove all data stored by websites on your computer.

    In the Safari menu, choose “Preferences…”, select “Privacy” at the top of the new window that appears, and then click the “Manage Website Data” button.
    Click Manage Website Data

    In the next dialog box, click “Remove All“. It will ask you if you are sure you want to remove all data stored by websites on your computer. Select “Remove Now” to clear data that could be used to track your browsing.

    Click Remove All Website Data

  7. Empty Safari Caches.

    From your Safari menu bar, click Safari and select Preferences, then select the Advanced tab. Enable the checkbox to “Show Develop menu in menu bar“.
    Show Dev Bar

    From the menu bar select Develop, then click on Empty Caches as seen in the image below.
    empty cache

Remove Malware and Spam Push Notifications from Chrome for Mac

To remove spam push notifications from Chrome for Mac we will reset the browser settings to its default. Doing these steps will erase all configuration information from Chrome such as your home page, tab settings, saved form information, browsing history, and cookies. This process will also disable any installed extensions. All of your bookmarks, though, will be preserved.

  1. Click on the three dots at the top right and go to Settings.

    Click on Chrome’s main menu button, represented by three dots at the top right corner. Now click on the menu option labeled Settings as shown by the arrow in the picture below, which will open the basic settings screen. Click on the Chrome menu button then on the Settings button
  2. In the left sidebar, click on the “Reset and Cleanup” option.

    In the left sidebar, click on “Reset and clean up“. Click on Reset and Cleanup
  3. Click “Reset settings to their original defaults”.

    Now click on the “Reset settings to their original defaults”. link as shown in the image below.  Reset Chrome
  4. Click “Reset Settings” button.

    A confirmation dialog should now be displayed, detailing the components that will be restored to their default state should you continue with the reset process. To complete the restoration process, click on the “Reset Settings” button. Confirm Reset Chrome browser
  5. (Optional) Reset Chrome Data Sync.

    In case a malicious extension reinstalls itself even after performing a browser reset, you have an additional option to reset the data sync for your browser. To do this, navigate to chrome.google.com/sync and click on the Clear Data button. Chrome Sync Reset
Remove Malware and Spam Push Notifications from Firefox for Mac

To remove spam push notifications from Firefox for Mac we will reset the browser settings to its default. The reset feature fixes many issues by restoring Firefox to its factory default state while saving your essential information like bookmarks, passwords, web form auto-fill information, browsing history, and open tabs.

  1. Go to the “Help” menu.

    Click on Firefox’s main menu button, represented by three horizontal lines. When the drop-down menu appears, select the option labeled “Help“.
    Image - Click on the Firefox Menu button then select Help

  2. Click “Troubleshooting Information”.

    Next click on the “Troubleshooting Information” option as indicated by the arrow in the image below. This will bring you to a Troubleshooting page.

    Image - Troubleshooting Information option in Firefox Mac

  3. Click on “Refresh Firefox”

    Click the “Refresh Firefox” button in the upper-right corner of the “Troubleshooting Information” page.
    Image - Click on the Refresh Firefox button Mac

  4. Confirm.

    To continue, click on the “Refresh Firefox” button in the new confirmation window that opens.
    Image - Click again on Refresh Firefox button

  5. Click on “Finish”.

    Firefox will close itself and will revert to its default settings. When it’s done, a window will list the information that was imported. Click on the “Finish“.

Your old Firefox profile will be placed on your desktop in a folder named “Old Firefox Data“. If the reset didn’t fix your problem you can restore some of the information not saved by copying files to the new profile that was created. If you don’t need this folder any longer, you should delete it as it contains sensitive information.
Now that we’ve removed the spam push notifications and malicious extensions from your browser, in the next step we will scan your Mac for any malware infections that may be present on your device.


STEP 2: Use Malwarebytes for Mac to remove Malware and Unwanted Programs

In this second step, we will download, install and run a scan with Malwarebytes to find and remove browser hijackers, adware, malicious browser extensions, and other malware from your Mac.

Malwarebytes for Mac is an on-demand scanner that can destroy many types of malware that other software tends to miss without costing you absolutely anything. When it comes to cleaning up an infected device, Malwarebytes has always been free, and we recommend it as an essential tool in the fight against malware.

  1. Download Malwarebytes for Mac.

    You can download Malwarebytes for Mac by clicking the link below.

    MALWAREBYTES FOR MAC DOWNLOAD LINK
    (The above link will open a new page from where you can download Malwarebytes for Mac)
  2. Double-click on the Malwarebytes setup file.

    When Malwarebytes has finished downloading, double-click on the setup file to install Malwarebytes on your computer. In most cases, downloaded files are saved to the Downloads folder.

    Double-click on setup file to install Malwarebytes

  3. Follow the on-screen prompts to install Malwarebytes.

    When the Malwarebytes installation begins, you will see the Malwarebytes for Mac Installer which will guide you through the installation process. Click “Continue“, then keep following the prompts to continue with the installation process.

    Click Continue to install Malwarebytes for Mac

    Click again on Continue to install Malwarebytes for Mac for Mac

    Click Install to install Malwarebytes on Mac

    When your Malwarebytes installation completes, the program opens to the Welcome to Malwarebytes screen. Click the “Get started” button.

  4. Select “Personal Computer” or “Work Computer”.

    The Malwarebytes Welcome screen will first ask you what type of computer are you installing this program, click either Personal Computer or Work Computer.
    Select Personal Computer or Work Computer mac

  5. Click on “Scan”.

    To scan your computer with Malwarebytes, click on the “Scan” button. Malwarebytes for Mac will automatically update the antivirus database and start scanning your computer for malware.
    Click on Scan button to start a system scan Mac

  6. Wait for the Malwarebytes scan to complete.

    Malwarebytes will scan your computer for adware, browser hijackers, and other malicious programs. This process can take a few minutes, so we suggest you do something else and periodically check on the status of the scan to see when it is finished.
    Wait for Malwarebytes for Mac to scan for malware

  7. Click on “Quarantine”.

    When the scan has been completed, you will be presented with a screen showing the malware infections that Malwarebytes has detected. To remove the malware that Malwarebytes has found, click on the “Quarantine” button.
    Review the malicious programs and click on Quarantine to remove malware

  8. Restart computer.

    Malwarebytes will now remove all the malicious files that it has found. To complete the malware removal process, Malwarebytes may ask you to restart your computer.
    Malwarebytes For Mac requesting to restart computer

Your Mac should now be free of the CumulusCongestus extension and other malware.

If your current antivirus allowed a malicious program on your computer, you might want to consider purchasing the full-featured version of Malwarebytes Anti-Malware to protect against these types of threats in the future.
If you are still experiencing problems while trying to remove a malicious program from your computer, please ask for help in our Mac Malware Removal Help & Support forum.

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How to Stay Safe Online

Here are 10 basic security tips to help you avoid malware and protect your device:

  1. Use a good antivirus and keep it up-to-date.

    Shield Guide

    It's essential to use a good quality antivirus and keep it up-to-date to stay ahead of the latest cyber threats. We are huge fans of Malwarebytes Premium and use it on all of our devices, including Windows and Mac computers as well as our mobile devices. Malwarebytes sits beside your traditional antivirus, filling in any gaps in its defenses, and providing extra protection against sneakier security threats.

  2. Keep software and operating systems up-to-date.

    updates-guide

    Keep your operating system and apps up to date. Whenever an update is released for your device, download and install it right away. These updates often include security fixes, vulnerability patches, and other necessary maintenance.

  3. Be careful when installing programs and apps.

    install guide

    Pay close attention to installation screens and license agreements when installing software. Custom or advanced installation options will often disclose any third-party software that is also being installed. Take great care in every stage of the process and make sure you know what it is you're agreeing to before you click "Next."

  4. Install an ad blocker.

    Ad Blocker

    Use a browser-based content blocker, like AdGuard. Content blockers help stop malicious ads, Trojans, phishing, and other undesirable content that an antivirus product alone may not stop.

  5. Be careful what you download.

    Trojan Horse

    A top goal of cybercriminals is to trick you into downloading malware—programs or apps that carry malware or try to steal information. This malware can be disguised as an app: anything from a popular game to something that checks traffic or the weather.

  6. Be alert for people trying to trick you.

    warning sign

    Whether it's your email, phone, messenger, or other applications, always be alert and on guard for someone trying to trick you into clicking on links or replying to messages. Remember that it's easy to spoof phone numbers, so a familiar name or number doesn't make messages more trustworthy.

  7. Back up your data.

    backup sign

    Back up your data frequently and check that your backup data can be restored. You can do this manually on an external HDD/USB stick, or automatically using backup software. This is also the best way to counter ransomware. Never connect the backup drive to a computer if you suspect that the computer is infected with malware.

  8. Choose strong passwords.

    lock sign

    Use strong and unique passwords for each of your accounts. Avoid using personal information or easily guessable words in your passwords. Enable two-factor authentication (2FA) on your accounts whenever possible.

  9. Be careful where you click.

    cursor sign

    Be cautious when clicking on links or downloading attachments from unknown sources. These could potentially contain malware or phishing scams.

  10. Don't use pirated software.

    Shady Guide

    Avoid using Peer-to-Peer (P2P) file-sharing programs, keygens, cracks, and other pirated software that can often compromise your data, privacy, or both.

To avoid potential dangers on the internet, it's important to follow these 10 basic safety rules. By doing so, you can protect yourself from many of the unpleasant surprises that can arise when using the web.