Macs that are invulnerable and totally immune from the risk of viruses is a false myth that must be debunked: even MacOS, the operating system of Apple computers, can be attacked by malware and, if you are not careful in using your computer, it can easily happen bump into unpleasant companies , such as malicious software that changes the home page and / or search engines of browsers or, worse still, the ransomware, which encrypt the data on the disk and then ask for a ransom in money to decrypt them.

Macs that are invulnerable and totally immune from the risk of viruses is a false myth that must be debunked: even MacOS, the operating system of Apple computers, can be attacked by malware and, if you are not careful in using your computer, it can easily happen bump into unpleasant companies , such as malicious software that changes the home page and / or search engines of browsers or, worse still, the ransomware, which encrypt the data on the disk and then ask for a ransom in money to decrypt them.

True, the risk of running into viruses on Mac is much lower than what you have on a Windows PC (mainly because the Microsoft operating system is much more widespread than the Apple and then the cybercriminals are focused on that ), but this does not mean that the computers of the “apple” are unassailable. How do you say? Did you notice why your Mac started to behave in a strange way and that it was attacked by malware? Do not worry, I can help you solve the problem.

Take five minutes of free time, take a look at the instructions below and find out how to clean Mac from viruses using some solutions suitable for this purpose. If you have been unlucky (and / or imprudent, because you have run software from unreliable sources) and now your Mac is infected with malware, putting into practice the “tips” I’m about to give you should be able to put your computer. Good reading and good luck for everything!

Use an antimalware

The first step you need to take to clean a Mac from viruses is to install good anti-malware software . There are many to choose from, but I recommend Malwarebytes for Mac , which is extremely effective, fast and manages to remove most malicious software designed for macOS.

Malwarebytes for Mac can be downloaded and used for free, but after 30 days its real-time protection module expires: to continue using it, you need to purchase the Premium version of the program at a cost of 39.99 euros / year . Personally I consider the protection in real time still superfluous on Mac (unless you are used to run non-certified software, coming from sources “little”, with a certain frequency), so you could also “settle” the free version and use it to check the system status from time to time.

Without this premise, let’s move on to action! To download Malwarebytes for Mac, connected to its official website and click on the Free Download button . When the download is complete, start the Malwarebytes-Mac-xx.pkg executable you have obtained and, in the window that opens, click in sequence on the Continue (for four consecutive times) and Accept buttons .

Pigia then on the Install button , type the password of your user account on macOS (the one you use to access the system), from the Enter and, at the end of the setup, click on Close and Move to close the window and delete the installation package of Malwarebytes for Mac.

Now you have an excellent anti-malware for Mac and a real-time protection against viruses, spyware, adware and other malware designed for macOS (protection that, I remind you, will remain active only for 30 days). If you find the superfluous real-time protection module, turn it off by starting Malwarebytes for Mac and clicking on the On option next to the Real-Time protection item (on the right) in the main program window, so that it becomes Off .

After adjusting the real-time protection settings, you need to start a full system scan. To do so, click on Scan Now button of Malwarebytes for Mac and wait patiently for the procedure to come to an end: it may take a few minutes.

When the scan is complete, if malware has been detected on your Mac, select the related items and proceed to quarantine them. You may be asked to restart your computer for the changes to take effect. On the other hand, if you see the words Congratulations, you are clean! , means that no known threats have been detected on the Mac.

If Malwarebytes for Mac has not fully satisfied you, to uninstall the program you have to start the program, go to the Help menu at the top and select the Uninstall Malwarebytes entry in the latter. If, however, you do not want to remove the program but only hide its icon in the menu bar (next to the system clock), go to the Malwarebytes > Preferences menu and put the check mark next to the entry Hide application icon in the window opens.

If you are looking for alternative solutions, try Bitdefender Virus Scanner : a free antivirus produced by Bitdefender, thanks to which you can check your system and remove all the most known threats for macOS. It does not include a real-time protection module (it only scans on-demand) but it can also recognize viruses for Windows (which on Mac do not do damage, but can be dangerous if you share files from macOS to Windows).

 

To download Bitdefender Virus Scanner, all you need to do is connect to the Mac App Store page that hosts it and press the Get / Install button . When installation is complete, then, to start a system check, you must first click on the End button (in order to accept the automatic signature update) and then on  Check critical paths . At this point, put the check mark next to the item  More protection , click on the Allow access button  , select Macintosh HD  from the drop-down menu in the window that opens and presses  Allow access to proceed with the scan.

If not even the Bitdefender antimalware can satisfy you fully, try to take a look at my post on the best antivirus for Mac : inside you will find many alternative solutions that could be for you.

Delete malicious extensions from the browser

If your problems are mainly about Web browsing and, for example, you are redirected to sites full of advertising, try checking the list of extensions in your browser and remove those that you suspect. Below you will find all the steps to be taken on the most popular browsers.

Safari – if you use Safari (the default macOS browser), you can check the list of extensions installed in it by going to the Safari> Preferences menu (top left) and selecting the Extensions tab from the window that opens. At this point, locate the suspicious extension from the left sidebar and remove it, clicking first on its name and then on the Uninstall button that appears on the right (giving confirmation of the operation).

Chrome – if you use Chrome, can you check the list of extensions installed in the browser by clicking on the button? (top right) and selecting the items Other instruments> Extensions from the menu that appears. In the new tab that opens in the browser, find the extension you want to delete and click on the icon of the trash bin next to it and then click on the Remove button .

Firefox – in Firefox, can you check the list of extensions installed in the browser by clicking on the button? located at the top right and going to Add-ons (in the menu that appears). In the tab that opens, select the item Extensions from the left sidebar, locate the add-on to remove and click on the Remove button placed in front of its name.

Enable macOS protections

Mac operating system, macOS , includes several functions that prevent and counter malware infections. The best known is called Gatekeeper and is the one that prevents the execution of software that comes from non-certified developers. Keeping the Gatekeeper function active (which is available in MacOS Lion 10.7.5 and later), the Mac does not run programs that are downloaded outside the Mac App Store and that are not traceable to certified developers, therefore of proven reliability: this It prevents you from running potentially dangerous software and therefore from “catching” malware.

To verify that the Gatekeeper function is enabled and correctly configured on your Mac, open System Preferences (the gear icon located on the Dock bar), go to Security and Privacy and select the General tab from the window that opens. At this point, if you see that next to the App Store and identified developers there is a check mark, do nothing: Gatekeeper is already configured correctly. Otherwise, click on the lock icon located at the bottom left, type the password of your user account on macOS (the one you use to access the system) and the Enter, then put the check mark next to the App Store and identified developers and you’re done.

The App Store option is also available , which would make the Mac even safer, but I think it is too limited as it only allows running programs downloaded from the Mac App Store. If you want more info on Gatekeeper and its operation, visit the official Apple website .

Another security feature included in macOS, less known, is Xprotect : a real antimalware, complete with database of signatures, that Apple silently updates over time and that automatically blocks the execution of malicious software. It is active by default, but its updates – which are essential for effective system protection – may be disabled.

To check whether or not updates for Xprotect are enabled (you can find the full history here ), open System Preferences , go to the App Store and make sure there is a check mark next to the Install system data files entry and security updates . If not, click on the lock icon located at the bottom left, type the password of your user account on macOS (the one you use to access the system) and the Enter . At this point, put the check mark next to the item Install the system data files and security updates and you’re done.

Once you have activated the security measures in macOS and downloaded a good antimalware (to be used from time to time to control the computer), you should be able to sleep relatively quiet sleep. In any case, do not believe to be “invincible”. If you download software from untrustworthy sites and bypass the macOS restrictions (accepting their execution despite system warnings) you may still encounter malware.

My advice, therefore, is to download programs from reliable sources (primarily the Mac App Store ) and absolutely avoid software from the BitTorrent network or from file hosting services (which very often are also illegal). Bypass Gatekeeper restrictions only with proven reliability software, such as LibreOffice , which does not come from Apple certified developers but is absolutely secure as a program.

Format the Mac

If after all my advice you have not yet managed to clean the Mac from viruses, I’m sorry, but you just have to go to the most drastic measures and format the computer . Formatting the computer means erasing all data stored on its disk and reinstalling the operating system (macOS) from scratch.

Before proceeding, therefore, make sure you have made a complete backup of all your data and have kept them in a safe place. To perform the backup you could use Time Machine and its recovery function, but currently having a “shabby” system, I do not recommend it: better to “manually” copy the files of your interest on an external disk and activate the synchronization of photos , videos, documents etc. on the cloud using services like iCloud Drive , Dropbox and Google Drive. By doing so, after restoring the system you can regain your data in a simple way, except for the applications, which you will have to redo “manually” from the Mac App Store or their official websites.

Once you’ve secured your data, to format your Mac, restart your computer and hold down the cmd + r keys during its power up phase to access the recovery mode . Then select Disk Utility , choose the  disk you want to format  (eg  Macintosh HD ) from the left sidebar and click on the Initialize button . In the window that opens, type the  name  you want to assign to the drive after formatting, set the  Mac OS Extended (Journaled)  and  GUID Partition Map options  in the drop-down menus located at the bottom and click on the Initialize button  .

In the window that opens, type the  name  you want to assign to the drive after formatting, set the  Mac OS Extended (Journaled)  and  GUID Partition Map options  in the drop-down menus located at the bottom and click on the Initialize button  .

After formatting the disk (which causes the deletion of all data in it), exit Disk Utility, go to  MacOS Installation , click on the Continue button  and follow the on-screen instructions to install a new copy of macOS. To complete the operation, the computer must be connected to the Internet (all the files of the operating system must be downloaded, which could take a long time). If you do not have an Internet connection, you need to create a USB stick with the macOS installation files.

You can find more information on how to reinstall MacOS and how to create a USB stick with operating system files in my tutorial on how to install macOS High Sierra (the latest version of macOS, at the time of writing).