Mac Virus

Remove MacOsDefender Mac “Malware” (Safari/Chrome/FF)

Parasite may reinstall itself multiple times if you don't delete its core files. We recommend downloading ComboCleaner to scan for malicious programs installed with it. This may save you hours and cut down your time to about 15 minutes. 

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More information about ComboCleaner and steps to uninstall. Please review ComboCleaner's EULA and Privacy Policy. Keep in mind, only ComboCleaner’s scanner is free. If it detects a malware, you'll need to purchase its full version to remove it.



MacOsDefender “Malware” is an adware-based application which is known to interrupt the users as they browse the web and asks them to click on various ads pop-ups and banners. The application usually comes in the form of a browser add-on or and thus easily enters popular browsers such as Safari, Chrome, and Firefox. The main reason why many users are bothered by the presence of MacOsDefender on their system is mainly due to its ability to spam their screens with offers and promotional messages of various kinds and to redirect their searches to sponsored websites. Typically, such adware applications may affect the main browser by slowing it down and making it become unresponsive to the users’ searches. They may also be related to certain risks such as exposure to misleading promotional content and potential redirects to malicious web pages.

Some people report that, in their attempts to remove the random ads and pop-ups, they have gotten exposed to vouchers and products with questionable quality as well as to offers that promise them some free features if they perform some action (for instance, downloading something, installing some new application or answering some query questions). Such behavior is common for the applications from the adware category since they are programmed to promote certain products, services and software and to make the users interact with the ads. However, carelessness from your side and one wrong click may not only land you nagging and hard-to-remove ads but also nasty viruses such as Ransomware or Trojans if you happen to get redirected to some harmful web locations. That’s why, in case that you have MacOsDefender on your PC, we would advise you to stay away from its content and take a look at the instructions in the removal guide below. The guide contains detailed steps on how to uninstall the advertising software and can help you rid of it without any risk for your system.

According to the reports of some users, MacOsDefender tends to redirect them to different links, described as “deals”, that can appear in the form of pop-up ads, ads in the background, or pop-up messages opened in a new tab. Others complain from the intrusiveness of the advertising content and say that they have been redirected to pages that ask them to fill their names, email addresses and other types of data in order to win a prize. Such behavior could easily be mistaken for some virus-like behavior and may lead to panic in some users. However, to your relief, adware apps do not normally have many common features with any more serious form of malware like Ransomware, Spyware, Trojans, etc. Usually, the main reason why you might want to uninstall the hijacker is its aggressive ads generation.

Such software cannot infect you in a stealthy way like a virus and is usually distributed through a marketing method called software bundling. This method allows the grouping of several applications together in a single installation bundle – typically, one main program and some bonus or additional applications. Unfortunately, a large number of users ignore the settings related to the additional applications when they run the main installer and this is how they end up with software like MacOsDefender on their PC. In order to avoid that, we recommend that you use the “User” or “Advanced” settings when installing new applications on your system because these options give you the freedom to choose which additional applications to install and which to leave behind. The “Standard” and “Default” installation settings seem reliable and convenient but, in most of the cases, they usually do not reveal any information about the bundled applications. That’s why the users should manually make their changes using the detailed installation settings in order to have full control over what gets installed in their systems.


Name MacOsDefender
Type  Adware
Danger Level Medium (nowhere near threats like Ransomware, but still a security risk)
Symptoms  Nagging ads may spam your screen and prompt you to click on various sponsored links. 
Distribution Method Most commonly found in program bundles, automatic installers and download managers, as well as spam, torrents and ads. 
Detection Tool

Remove MacOsDefender “Malware”


We get asked this a lot, so we are putting it here: Removing parasite manually may take hours and damage your system in the process. We recommend downloading ComboCleaner to see if it can detect parasite files for you.

The first thing you need to do is to Quit Safari (if it is opened). If you have trouble closing it normally, you may need to Force Quit Safari:

You can choose the Apple menu and click on Force Quit.

Alternatively you can simultaneously press (the Command key situated next to the space bar), Option (the key right next to it) and Escape (the key located at the upper left corner of your keyboard).

If you have done it right a dialog box titled Force Quit Applications will open up.

In this new dialog window select Safari, then press the Force Quit button, then confirm with Force Quit again.

Close the dialog box/window.



To remove parasite on your own, you may have to meddle with system files and registries. If you were to do this, you need to be extremely careful, because you may damage your system.

If you want to avoid the risk, we recommend downloading ComboCleaner
a professional malware removal tool.

More information on ComboCleaner, steps to uninstallEULA, and Privacy Policy.

Start Activity Monitor by opening up Finder, then proceed to activity-monitor

Once there, look at all the processes: if you believe any of them are hijacking your results, or are part of the problem, highlight the process with your mouse, then click the “i” button at the top. This will open up the following box:


Now click on Sample at the bottom:


Do this for all processes you believe are part of the threat, and run any suspicious files in our online virus scanner, then delete the malicious files:

Drag and Drop Files Here to Scan
Maximum file size: 128MB.

This scanner is free and will always remain free for our website's users. You can find its full-page version at:

Scan Results

Virus Scanner Result


The next step is to safely launch Safari again. Press and hold the Shift key while relaunching Safari. This will prevent Safari’s previously opened pages from loading again. Once Safari is opened up, you can release the Shift key.

On the off chance that you are still having trouble with scripts interrupting the closing of unwanted pages in Safari, you may need to take some additional measures.

First, Force Quit Safari again.

Now if you are using a Wi-Fi connection turn it off by selecting Wi-Fi off in you Mac’s Menu. If you are using a cable internet (Ethernet connection), disconnect the Ethernet cable.


Re-Launch Safari but don’t forget to press and hold the Shift button while doing it, so no previous pages can be opened up. Now, Click on Preferences in the Safari menu,

Preferences in Safari

and then again on the Extensions tab,

extensions in safari

Select and Uninstall any extensions that you don’t recognize by clicking on the Uninstall button. If you are not sure and don’t want to take any risks you can safely uninstall all extensions, none are required for normal system operation.

The threat has likely infected all of your browsers. The instructions below need to be applied for all browsers you are using.

Again select Preferences in the Safari Menu, but this time click on the Privacy tab,
Privacy in Safari

Now click on Remove All Website Data, confirm with Remove Now. Keep in mind that after you do this all stored website data will be deleted. You will need to sign-in again for all websites that require any form of authentication.

Still in the Preferences menu, hit the General tab

General Tab in Safari

Check if your Homepage is the one you have selected, if not change it to whatever you prefer.
Default Home Page

Select the History menu this time, and click on Clear History. This way you will prevent accidentally opening a problematic web page again.

firefox-512 How to Remove MacOsDefender From Firefox in OSX:

Open Firefoxclick on mozilla menu (top right) ——-> Add-onsHit Extensions next.

pic 6

The problem should be lurking somewhere around here –  Remove it. Then Refresh Your Firefox Settings.

chrome-logo-transparent-backgroundHow to Remove MacOsDefender From Chrome in OSX:

 Start Chrome, click chrome menu icon —–>More Tools —–> Extensions. There,  find the malware and  select  chrome-trash-icon.

pic 8

 Click chrome menu icon again, and proceed to Settings —> Search, the fourth tab, select Manage Search Engines.  Delete everything but the search engines you normally use. After that Reset Your Chrome Settings.

If the guide doesn’t help, download the anti-virus program we recommended or try our free online virus scanner. Also, you can always ask us in the comments for help!

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