Avoid downloading dubious applications from Chksumm deceptive websites

Also Known As: Chksumm pop-up
Type: Mac Virus
Distribution: Low
Damage level: Medium

How to remove "Chksumm" from Mac computers

What is "Chksumm"?

Chksumm is a family of scam websites designed to promote dubious applications, which are typically fake and nonfunctional. This variant promotes the Smart Mac Booster Potentially Unwanted Application (PUA). The deceptive web pages show alerts of various 'threats' and 'issues' supposedly found on visitors' devices and offer software for their elimination. Note that no website can detect problems within operating systems. Therefore, such claims cannot be trusted. Most visits to Chksumm occur inadvertently, often via redirects caused by intrusive advertisements or PUAs.

Chksumm scam

Once accessed, Chksumm displays a pop-up window containing a message that claims that a website visited earlier has infected the MacOS (Mac Operating System) with a virus. Pressing "OK" will allegedly begin the repair process. When visitors close the pop-up, the site shows a different web page that reiterates the warning from the previous window and adds that a 'full system scan' is required to locate and remove the harmful files/applications. Furthermore, the page lists the user's device details, such as brand, OS version, browser, IP address, Internet provider, and location. The "Scan Now" button starts a fake scan, which "detects" a high-risk virus called "Bankworm". To eliminate this threat, Chksumm recommends Advanced Mac Cleaner. Attempting to obtain this application leads users to the promotional web page of Smart Mac Booster. Following the instructions to download the app actually results in download of the maccleaner.pkg file, which is known to proliferate PUAs. It spreads unwanted applications other than Smart Mac Booster including Advanced Mac TuneupMac Cleanup ProMacKeeper, and dozens of others. Software of this type usually requires purchase to become operational, however, even after payment, it tends to remain nonoperational.

In general, PUAs share many similarities. They may seem legitimate and offer a broad array of "useful" features, which are often nonfunctional. As mentioned, these apps generate redirects to untrustworthy, deceptive/scam and malicious sites. They can also deliver intrusive advertisements by employing tools to enable third party graphical content to be displayed on any site. The ads diminish the browsing experience (i.e., overlay web pages, thereby limiting visibility and browsing speed), redirect to dangerous websites, and stealthily download/install PUAs. Unwanted applications can also hijack browsers. Data tracking capabilities are a major concern with PUAs. They often record browsing activity (browsing and search engine histories) and gather users' personal information (IP addresses, geolocations, and other details). This data is then shared with third parties (potentially, cyber criminals) seeking to misuse it for financial gain. In summary, PUAs can cause browser/system infiltration and infections, and lead to financial loss, serious privacy issues and even identity theft. To ensure device and user safety, remove all suspicious applications and browser extensions/plug-ins without delay.

Threat Summary:
Name Chksumm pop-up
Threat Type Phishing, Scam, Mac malware, Mac virus.
Fake Claim Chksumm websites claim that devices are infected with a virus and encourages users to download cleaning software.
Detection Names Kaspersky (Malware), Full List (VirusTotal)
Serving IP Address 193.35.51.7
Related Domains Full list below.
Promoted Unwanted Application Smart Mac Booster
Symptoms Your Mac becomes slower than normal, you see unwanted pop-up ads, you are redirected to dubious websites.
Distribution methods Deceptive pop-up ads, free software installers (bundling), fake Flash Player installers, torrent file downloads.
Damage Internet browser tracking (potential privacy issues), display of unwanted ads, redirects to dubious websites, loss of private information.
Malware Removal (Mac)

To eliminate possible malware infections, scan your Mac with legitimate antivirus software. Our security researchers recommend using Combo Cleaner.
▼ Download Combo Cleaner for Mac
To use full-featured product, you have to purchase a license for Combo Cleaner. Limited three days free trial available.

The Internet is rife with scam websites, which tend to share certain similarities and some are even identical. For example, TrksmmNothsws, Zxcvc are identical to Chksumm. These web pages use scare tactics, mainly for the purpose of endorsing bogus and nonoperational software. They operate by scaring visitors with alarms of detected "threats" and push them into installing and/or purchasing untrustworthy apps. Few users enter deceptive pages intentionally, most are redirected by PUAs or by intrusive ads.

How did potentially unwanted applications install on my computer?

PUAs are commonly downloaded/installed together with other software. This deceptive marketing method of pre-packing regular content with these applications is called "bundling". By rushing through download/installation processes (e.g. skipping steps, using pre-set options, etc.), many users endanger their devices with potential system infiltration and infections. Some PUAs have "official" download sites on which they are often endorsed as "free" and "useful". When clicked, intrusive advertisements can execute scripts designed to download/install unwanted content without users' permission.

How to avoid installation of potentially unwanted applications

Research all products before downloading/installing. Use only official and verified download channels. Peer-to-Peer sharing networks (BitTorrent, Gnutella, eMule, etc.), free file-hosting websites and other third party downloaders are classed as untrustworthy and should be avoided. Treat download and installation processes with caution. Read the terms, explore all possible options, use the "Custom/Advanced" settings, and opt-out of downloading/installing additional apps, tools, functions, etc. Intrusive ads usually seem normal and harmless, however, they often redirect to dubious web pages (e.g. gambling, adult-dating, pornography, and others). If you encounter ads/redirects of this kind, inspect the device and immediately remove all suspicious applications and/or browser extensions/plug-ins. If your computer is already infected with PUAs, we recommend running a scan with Combo Cleaner Antivirus for macOS to automatically eliminate them.

Text presented in the pop-up window:

VIRUS FOUND

A website you visited today has infected your Mac with a virus.

Press OK to begin the repair process.

Screenshot of the second web page displayed by Chksumm:

chksumm second page

Text presented on this page:

VIRUS FOUND
A website you have visited today has infected your Mac with a virus. A full system scan is now required to find and remove harmful files or applications from your Mac OS X 10_13_6 device.
DEVICE INFORMATION
Brand: Apple
Device: Mac OS X 10_13_6
Browser: Safari 12.0.1
IP: 85.206.10.62
Provider: Telia Lietuva, AB
Location: - LT
Scan Now

Screenshot of the fake system scan results:

chksumm fake scan

Text presented in this page:

DOWNLOAD REQUIRED
Please download the Advanced Mac Cleaner application to remove Bankworm from your Mac.
VIRUS INFORMATION
Virus Name: Bankworm
Risk: HIGH
Infected File: /os/apps/worm.icv
VIRUS REMOVAL
Application: Advanced Mac Cleaner
Rating: 9.9/10
Price: Free
REMOVE VIRUS NOW

Appearance of "Chksumm" scam (GIF):

Appearance of Chksumm scam (GIF)

List of domains relating to the Chksumm website family:

chksumm55[.]live chksumm62[.]live
chksumm56[.]live chksumm73[.]live

Screenshot of the Smart Mac Booster installation set-up:

chksumm installer

Screenshot of the Smart Mac Booster application:

chksumm app

Instant automatic Mac malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Combo Cleaner is a professional automatic malware removal tool that is recommended to get rid of Mac malware. Download it by clicking the button below:
▼ DOWNLOAD Combo Cleaner for Mac 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. Limited three days free trial available.

Quick menu:

Video showing how to remove unwanted applications promoted via Chksumm websites using Combo Cleaner:

Potentially unwanted applications removal:

Remove potentially unwanted applications from your "Applications" folder:

mac browser hijacker removal from 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 chksumm pop-up related files and folders:

Finder go to folder command

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

step1Check for adware-generated files in the /Library/LaunchAgents folder:

removing adware from launch agents folder step 1

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

removing adware from launch agents folder step 2
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 same string.

step2Check for adware generated files in the /Library/Application Support folder:

removing adware from application support folder step 1

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

removing adware from application support folder step 2
In the “Application Support” folder, look for any recently-added suspicious folders. For example, “MplayerX” or “NicePlayer”, and move these folders to the Trash.

step3Check for adware-generated files in the ~/Library/LaunchAgents folder:

removing adware from ~launch agents folder step 1


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

removing adware from ~launch agents folder step 2

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 same string.

step4Check for adware-generated files in the /Library/LaunchDaemons folder:

removing adware from launch daemons folder step 1
In the Go to Folder... bar, type: /Library/LaunchDaemons

removing adware from launch daemons folder step 2
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.

step 5 Scan your Mac with Combo Cleaner:

If you have followed all the steps in the correct order you Mac should be clean of infections. To be sure 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 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 it's virus definition database and click "Start Combo Scan" button.

scan-with-combo-cleaner-1

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.

scan-with-combo-cleaner-2

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

Chksumm pop-up removal from Internet browsers:

safari browser iconRemove malicious extensions from Safari:

Remove chksumm pop-up related Safari extensions:

safari browser preferences

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

safari extensions window

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 normal browser operation.

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

firefox browser iconRemove malicious plug-ins from Mozilla Firefox:

Remove chksumm pop-up related Mozilla Firefox add-ons:

accessing mozilla firefox add-ons

Open your Mozilla Firefox browser. At the top right corner of the screen, click the "Open Menu" (three horizontal lines) button. From the opened menu, choose "Add-ons".

removing malicious add-ons from mozilla firefox

Choose the "Extensions" tab and look for any recently-installed suspicious add-ons. When located, click the "Remove" button next to it/them. Note that you can safely uninstall all extensions from your Mozilla Firefox browser - none are crucial for normal browser operation.

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

chrome-browser-iconRemove malicious extensions from Google Chrome:

Remove chksumm pop-up related Google Chrome add-ons:

removing malicious google chrome extensions step 1

Open Google Chrome and click the "Chrome menu" (three horizontal lines) button located in the top-right corner of the browser window. From the drop-down menu, choose "More Tools" and select "Extensions".

removing malicious Google Chrome extensions step 2

In the "Extensions" window, look for any recently-installed suspicious add-ons. When located, click the "Trash" button next to it/them. Note that you can safely uninstall all extensions from your Google Chrome browser - none are crucial for normal browser operation.

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

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.

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Malware activity

Global malware activity level today:

Medium threat activity

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

QR Code
Chksumm pop-up QR code
A QR code (Quick Response Code) is a machine-readable code which stores URLs and other information. This code can be read using a camera on a smartphone or a tablet. Scan this QR code to have an easy access removal guide of Chksumm pop-up on your mobile device.
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