How to remove CheckLetter adware from the operating system?

What is CheckLetter?

CheckLetter is a rogue app classified as adware. It also has browser hijacker qualities. Furthermore, due to the questionable techniques used to distribute software products of this type, they are also considered to be PUAs (Potentially Unwanted Applications).

CheckLetter adware overview

Adware can display pop-ups, banners, coupons, and other intrusive advertisements on any visited website and/or different interfaces. They diminish the browsing experience by limiting webpage visibility and slowing down the browsing speed.

The delivered ads can be misleading, deceptive, and even dangerous. They promote various untrustworthy and even malicious sites. What is more, some intrusive adverts can be triggered (by being clicked on) to stealthily download/install software (e.g., PUAs).

Browser hijackers reassign browsers' homepage, default search engine, and new tab/window URLs to fake web searchers. Hence, every web search performed via the URL bar and new tab/window opened - redirect to the promoted address.

Fake search engines usually cannot provide search results, so they redirect to Google, Bing, Yahoo, and other genuine ones. Browser hijackers also use persistence-ensuring techniques to prevent users from recovering their browsers.

Adware and browser hijackers typically have data tracking abilities. They monitor browsing activity (URLs visited, pages viewed, search queries typed, etc.) and collect sensitive data extracted from it (IP addresses, personally identifiable details, etc.). The gathered information is then shared with and/or sold to third-parties.

In summary, the presence of unwanted apps on devices can lead to system infections, severe privacy issues, financial losses, and even identity theft.

Adware in general

AboutDynamic, UpgradeSearchView, and ModeService are a few examples of adware. This software appears harmless and offers "handy" features, which rarely work. In fact, functionality and user safety are irrelevant for practically all PUAs, as their sole goal is to generate revenue for the developers.

How did CheckLetter install on my computer?

PUAs are spread using the "bundling" marketing tactic - packing regular programs with various additions. Rushed downloads/installations increase the risk of allowing bundled content into the device. Intrusive adverts proliferate PUAs as well. Once clicked on, the ads can execute scripts to download/install these apps without user permission. Some PUAs also have "official" promotional/download sites.

How to avoid installation of potentially unwanted applications?

It is advised to research software and only download from official/verified sources. Untrustworthy download channels, e.g., unofficial and free file-hosting websites, Peer-to-Peer sharing networks, etc. - commonly offer bundled content.

When downloading/installing, it is recommended to read terms, study available options, use the "Custom/Advanced" settings, and opt-out from all supplements. Intrusive advertisements appear legitimate, yet they redirect to unreliable and questionable sites (e.g., pornography, gambling, adult-dating, etc.).

In case of encounters with such ads and/or redirects, the device must be inspected and all suspicious applications and browser extensions/plug-ins detected - removed from it without delay. If your computer is already infected with CheckLetter, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate this adware.

Pop-up window displayed once CheckLetter adware's installation is over:

CheckLetter adware's installation folder:

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:

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.

Quick menu:

• What is CheckLetter?
• STEP 1. Remove CheckLetter related files and folders from OSX.
• STEP 2. Remove CheckLetter ads from Safari.
• STEP 3. Remove CheckLetter adware from Google Chrome.
• STEP 4. Remove CheckLetter ads from Mozilla Firefox.

Video showing how to remove CheckLetter adware using Combo Cleaner:

CheckLetter adware removal:

Remove CheckLetter-related potentially unwanted applications from your "Applications" folder:

Click the Finder icon. In the Finder window, select "Applications". In the applications folder, look for "MPlayerX","NicePlayer", or other suspicious applications and drag them to the Trash.

After removing the potentially unwanted application(s) that cause online ads, scan your Mac for any remaining unwanted components.

Remove adware-related files and folders

Click the Finder icon, from the menu bar. Choose Go, and click Go to Folder...

Check for adware generated files in the /Library/LaunchAgents/ folder:

In the Go to Folder... bar, type: /Library/LaunchAgents/

In the "LaunchAgents" folder, look for any recently-added suspicious files and move them to the Trash. Examples of files generated by adware - "installmac.AppRemoval.plist", "myppes.download.plist", "mykotlerino.ltvbit.plist", "kuklorest.update.plist", etc. Adware commonly installs several files with the exact same string.

Check for adware generated files in the ~/Library/Application Support/ folder:

In the Go to Folder... bar, type: ~/Library/Application Support/

In the "Application Support" folder, look for any recently-added suspicious folders. For example, "MplayerX" or "NicePlayer", and move these folders to the Trash.

Check for adware generated files in the ~/Library/LaunchAgents/ folder:

In the Go to Folder... bar, type: ~/Library/LaunchAgents/

In the "LaunchAgents" folder, look for any recently-added suspicious files and move them to the Trash. Examples of files generated by adware - "installmac.AppRemoval.plist", "myppes.download.plist", "mykotlerino.ltvbit.plist", "kuklorest.update.plist", etc. Adware commonly installs several files with the exact same string.

Check for adware generated files in the /Library/LaunchDaemons/ folder:

In the "Go to Folder..." bar, type: /Library/LaunchDaemons/

In the "LaunchDaemons" folder, look for recently-added suspicious files. For example "com.aoudad.net-preferences.plist", "com.myppes.net-preferences.plist", "com.kuklorest.net-preferences.plist", "com.avickUpd.plist", etc., and move them to the Trash.

Scan your Mac with Combo Cleaner:

If you have followed all the steps correctly, your Mac should be clean of infections. To ensure your system is not infected, run a scan with Combo Cleaner Antivirus. Download it HERE. After downloading the file, double click combocleaner.dmg installer. In the opened window, drag and drop the Combo Cleaner icon on top of the Applications icon. Now open your launchpad and click on the Combo Cleaner icon. Wait until Combo Cleaner updates its virus definition database and click the "Start Combo Scan" button.

Combo Cleaner will scan your Mac for malware infections. If the antivirus scan displays "no threats found" - this means that you can continue with the removal guide; otherwise, it's recommended to remove any found infections before continuing.

After removing files and folders generated by the adware, continue to remove rogue extensions from your Internet browsers.

Remove malicious extensions from Internet browsers

Remove malicious Safari extensions:

Open the Safari browser, from the menu bar, select "Safari" and click "Preferences...".

In the preferences window, select "Extensions" and look for any recently-installed suspicious extensions. When located, click the "Uninstall" button next to it/them. Note that you can safely uninstall all extensions from your Safari browser - none are crucial for regular browser operation.

• If you continue to have problems with browser redirects and unwanted advertisements - Reset Safari.

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 extensions, select these entries and click "Remove".

• If you continue to have problems with browser redirects and unwanted advertisements - Reset Google Chrome.

Remove malicious extensions from Mozilla Firefox:

Click the Firefox menu (at the top right corner of the main window) and select "Add-ons and themes". Click "Extensions", in the opened window locate all recently-installed suspicious extensions, click on the three dots and then click "Remove".

• If you continue to have problems with browser redirects and unwanted advertisements - Reset Mozilla Firefox.

Frequently Asked Questions (FAQ)

What harm can adware cause?

Adware can negatively affect the browsing experience and system performance. Additionally, most adware-type apps can track data - which makes them a threat to user privacy. Furthermore, adware-delivered adverts can promote deceptive/malicious content that can cause other serious issues.

What does adware do?

Advertising-supported software or adware - is designed to run intrusive advertisement campaigns. In other words, this software can display various ads on any visited website and/or different interfaces.

How do adware developers generate revenue?

Adware generates revenue through affiliate programs by promoting sites, software, services, and similar. The developers of this software can earn commission from ad clicks, website visits, file downloads, product purchases, service subscriptions, etc.

Will Combo Cleaner remove CheckLetter adware?

Yes, Combo Cleaner is capable of scanning devices and eliminating installed adware-type applications. It is noteworthy that manual removal is not always a perfect solution. In some cases, even after the adware is eliminated - leftover files remain hiding in the system. Furthermore, such components may continue running and causing problems.