How to uninstall CheckLetter app/extension from Mac (Virus removal guide)

What is CheckLetter

CheckLetter is an adware application that targets Mac platform. Adware is form of malicious software designed to insert advertisements into Internet browsing or even desktop experience. CheckLetter can alter your homepage, search provider, search results, or even add toolbars to your web-browser. It run in the background when surf the Web, and it can slow down your web-browser and affect its performance.

The worst is, the adware can install a component that enables its developers to track which web pages you visit, which products you look at upon those pages. They are then able to choose the type of advertisements they display you. So, if you had adware software on your machine, there is a good chance you have another that is collecting and sharing your personal information with third parties, without your say-so.

How does CheckLetter get on your computer

Adware usually comes bundled with some freeware that users download off of the World Wide Web. So, think back, have you ever download and run any freeware. In order to avoid infection, in the Setup wizard, you should be be proactive and carefully read the ‘Terms of use’, the ‘license agreement’ and other install screens, as well as to always select the ‘Manual’ or ‘Advanced’ setup type, when installing anything downloaded from the World Wide Web.

Threat Summary

Name	CheckLetter, CheckLetter 1.0 app
Type	adware, potentially unwanted application (PUA), Mac malware, Mac virus
Detection Names	ApplicUnwnt, MacOS.Agent-MT, Trojan-Downloader.OSX.Adload, Osx.Adware.Cimpli, Adware/Adload!OSX, Program:MacOS/Vigram.A, OSX.Trojan.Gen and Adware.MAC.Generic
Distribution	Freeware installers, dubious popup advertisements, torrent downloads and fake updaters
Symptoms	Every time you perform an Internet search, your internet browser is redirected to another web site, you experience a huge count of of unexpected advertising pop ups, there is an unwanted program in the ‘Applications’ section of the Finder, new extensions suddenly added on your browser, your browser homepage has changed and you are unable to change it back, speed test good but internet slow.
Removal	CheckLetter removal guide

How to remove CheckLetter

Without a doubt, the adware software is harmful to your Mac. So you need to quickly and completely remove CheckLetter. To remove this adware, you can use the manual removal guide which are given below or free malware removal tools such as MalwareBytes Free (it is free). We recommend you use automatic removal solution which will allow you to get rid of CheckLetter adware easily and safely. Manual removal is best used only if you are well versed in machine or in the case where adware software is not removed automatically. Certain of the steps will require you to restart your machine or close this web site. So, read this guide carefully, then bookmark this page or open it on your smartphone for later reference.

To remove CheckLetter, execute the steps below:

1. Remove unwanted profiles on Mac device
2. Remove CheckLetter associated software by using the Finder
3. Remove CheckLetter related files and folders
4. Scan your Mac with MalwareBytes
5. Remove CheckLetter from Safari, Chrome, Firefox
6. How to stay safe online

Remove unwanted profiles on Mac device

CheckLetter can make changes to the Mac system such as malicious changes to browser settings, and the addition of malicious system profiles. You need to check the system preferences, find and remove malicious profiles and ensure your settings are as you expect.

Click the System Preferences icon ( ) in the Dock, or choose Apple menu ( ) > System Preferences.

In System Preferences, click Profiles, then select a profile associated with CheckLetter.

Click the minus button ( – ) located at the bottom-left of the Profiles screen to remove the profile.
Note: if you do not see Profiles in the System Preferences, that means there are no profiles installed on your Mac device, which is normal.

Remove CheckLetter associated software by using the Finder

Go to the Finder and delete dubious apps, all programs you don’t remember installing. It’s important to pay the most attention to applications you have recently installed. If you don’t know what a program does, look for the answer on the World Wide Web.

1. Open the Finder.
2. Click “Applications”.
3. It will display a list of all programs installed on the computer.
4. Scroll through the all list, and delete suspicious and unknown apps. Pay maximum attention to the application you installed last.
5. Drag the questionable application from the Applications folder to the Trash.
6. Empty Trash.

Remove CheckLetter related files and folders

Now you need to try to find CheckLetter related files and folders, and then delete them manually. You need to look for these files in certain directories. To quickly open them, we recommend using the “Go to Folder…” command.

CheckLetter creates several files, these files must be found and removed. Below is a list of files associated with this unwanted program.

• /Library/LaunchDaemons/com.CheckLetter.system.plist
• ~/Library/LaunchAgents/com.CheckLetter.service.plist
• /Library/Application Support/.(RANDOM)/System/com.CheckLetter.system
• ~/Library/Application Support/.(RANDOM)/Services/com.CheckLetter.service.app

Some files created by CheckLetter are hidden from the user. To find and delete them, you need to enable “show hidden files”. To do this, use the shortcut CMD + SHIFT + . Press once to show hidden files and again to hide them. There is another way. Click Finder -> Applications -> Utilities -> Terminal. In Terminal, paste the following text: defaults write com.apple.finder AppleShowAllFiles YES

Press Enter. Hold the ‘Option/alt’ key, then right click on the Finder icon in the dock and click Relaunch.

Click on the Finder icon. From the menu bar, select Go and click “Go to Folder…”. As a result, a small window opens that allows you to quickly open a specific directory.

Check for CheckLetter generated files in the /Library/LaunchAgents folder

In the “Go to Folder…” window, type the following text and press Go:
/Library/LaunchAgents

This will open the contents of the “/Library/LaunchAgents” folder. Look carefully at it and pay special attention to recently created files, as well as files that have a suspicious name. Move all suspicious files to the Trash. A few examples of files: com.machelper.plist, com.CheckLetter.service.plist, macsearch.plist, com.net-preferences.plist, installapp.plist, search.plist and com.google.defaultsearch.plist, . Most often, potentially unwanted programs, adware and browser hijackers create several files with similar names.

Check for CheckLetter generated files in the /Library/Application Support folder

In the “Go to Folder…” window, type the following text and press Go:
/Library/Application Support

This will open the contents of the “Application Support” folder. Look carefully at its contents, pay special attention to recently added/changed folders and files. Check the contents of suspicious folders, if there is a file with a name similar to com.CheckLetter.system, then this folder must be deleted. Move all suspicious folders and files to the Trash.

Check for CheckLetter generated files in the “~/Library/LaunchAgents” folder

In the “Go to Folder…” window, type the following text and press Go:
~/Library/LaunchAgents

Proceed in the same way as with the “/Library/LaunchAgents” and “/Library/Application Support” folders. Look for suspicious and recently added files. Move all suspicious files to the Trash.

Check for CheckLetter generated files in the /Library/LaunchDaemons folder

In the “Go to Folder…” window, type the following text and press Go:
/Library/LaunchDaemons

Carefully browse the entire list of files and pay special attention to recently created files, as well as files that have a suspicious name. Move all suspicious files to the Trash. A few examples of files to be deleted: com.macsearch.system.plist, com.machelper.system.plist, com.search.system.plist, com.CheckLetter.system.plist and com.installapp.system.plist. In most cases, potentially unwanted programs, adware software and browser hijackers create several files with similar names.

Scan your Mac with MalwareBytes

You can get rid of CheckLetter related files automatically with a help of MalwareBytes Anti Malware (MBAM). We recommend this free malicious software removal tool because it can easily remove adware, toolbars, PUPs and browser hijackers with all their components such as files, folders and system entries.

1. Visit the page linked below to download MalwareBytes AntiMalware.
   
   

   Malwarebytes Anti-malware (Mac)
   20841 downloads
   Author: Malwarebytes
   Category: Security tools
   Update: September 10, 2020
   
2. After the download is complete, please close all software and open windows on your Apple Mac. Run the downloaded file. Follow the prompts.
3. The MalwareBytes Anti Malware will run and display the main window.
4. Further, press the “Scan” button to perform a system scan for the CheckLetter adware. Depending on your Apple Mac, the scan can take anywhere from a few minutes to close to an hour. When a threat is found, the number of the security threats will change accordingly.
5. After MalwareBytes Free has completed scanning, MalwareBytes Anti-Malware will open a scan report.
6. All detected items will be marked. You can delete them all by simply press the “Remove Selected Items” button.
7. Close the Anti Malware and continue with the next step.

Remove CheckLetter from Safari, Chrome, Firefox

Annoying CheckLetter adware or other symptoms of adware in your browser is a good reason to locate and remove harmful plugins. This is an easy way to recover web browsers settings and not lose any important information.

Google Chrome	Mozilla Firefox
In the top right corner, click on Google Chrome’s main menu button, represented by three vertical dots. When the drop-down menu appears, choose ‘More tools’ and click on ‘Extensions’. Click ‘Remove’ to uninstall an extension. Click ‘Remove’ in the dialog box. You can also try to delete CheckLetter adware by reset Chrome settings.	Click on ‘menu’ button and select ‘Add-ons’. Go to ‘Extensions’ tab. To uninstall an add-on, click on ‘Remove’ button next to it. If you are still experiencing issues with CheckLetter adware removal, you need to reset Mozilla Firefox browser.
Safari
On the top menu select ‘Safari’, then ‘Preferences’. Select ‘Extensions’ tab. Select an extension you want to delete and click ‘Uninstall’ button next to it.

How to stay safe online

We recommend to install an ad blocking program. The adblocker utility such as AdGuard is a program which basically removes advertising from the Net and stops access to malicious web-sites. Moreover, security experts says that using adblocker apps is necessary to stay safe when surfing the World Wide Web.

Visit the following page to download AdGuard.

When the downloading process is finished, run the downloaded file. The “Setup Wizard” window will show up on the computer screen.

Follow the prompts. AdGuard will then be installed. A window will show up asking you to confirm that you want to see a quick tutorial. Click “Skip” button to close the window and use the default settings, or click “Get Started” to see an quick tutorial which will assist you get to know AdGuard better.

Each time, when you launch your MAC OS, AdGuard will start automatically and stop unwanted pop up advertisements, block malicious and misleading web pages.

To sum up

After completing the guidance above, your MAC OS should be clean from the CheckLetter adware and other malware. Firefox, Chrome and Safari will no longer display any unwanted ads. Unfortunately, if the few simple steps does not help you, then you have caught a new adware, and then the best way – ask for help here.