Does my computer have a virus? Check your Mac

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Have you wondered how to check your Mac if it is running slow or you are experiencing pop ups? Often a client will come to the SDM Shop and say one of the following:

my Mac is running slowly
I have a lot of pop up windows
I think I have a virus

While it is still rare for a Macintosh computer to have an actual virus, there are many malware programs, and other things that can slow down your Mac. Here is the list of actions that we would start with to help someone check their Mac, followed by detailed steps for each.

Check disk storage space
Check startup programs
Restart the computer
Run any updates needed
Check Activity Monitor
Delete browser extensions
Run Disk Utility
Uninstall apps
Run Malwarebytes

Before running any repair steps, please make sure your computer is backed up. This will protect your data.

Restart the Computer

There is a big difference between what the computer does when it goes to sleep, and what it does when it shuts down or restarts (shut down plus start again). There are many internal cleanup routines that only happen when a computer shuts down. For this reason, it is useful to fully shut down your computer routinely. It does not have to be daily, but possibly weekly, and it is always the first thing we do when there is any issue.

Apple icon menu (top left)
Shut Down or Restart

Occasionally, the computer will need to be forced to shut down by holding down the power button for several seconds. Rarely, but sometimes, you will need to do this several times to get an error to clear itself.

Check disk storage space

If your computer is using most of its built in storage space, this can cause it to slow down and experience errors. So, the next step to check your Mac is to see how much storage space you have, and what is currently in use. To do this, follow these steps:

Click on the Apple icon to open the menu
Then Click on About this Mac

Finally Click on the Storage tab

The graph displayed will show you the total storage, the amount used, and a general idea of the kinds of files using this storage. By hovering your mouse over a section, you can see the name and the exact measurement of that section. The dark grey Other section is generally the operating system and backups.

If you click on the word Manage, you will be taken to a list of recommendations which you can then step through. Once you know what is taking up your storage space, it is easier to have a discussion about what your options are to clear out some space.

Check Startup programs

Every computer has the ability to start up selected programs when the computer is turned on. This can be useful when you use the same few programs every time. While this will slow down the start up of your computer, it can also save you some time if the first thing you have to do is start those same programs.

Unfortunately, sometimes a program is given permission to join this start up routine when you don’t actually need it. In addition, turning off some of the start up programs will sometimes clear out unintended issues. To check your Mac and see what programs are in your start up group, follow these steps:

Open System Preferences
Click on Users and Groups in the second row

Click on the Lock in the lower left and enter your computer log in password. This will allow you to make changes.
Click on your User Name
Click on Login Items Tab next to the Password Tab

This will display a list of the programs that turn on automatically when you start up your computer.

To delete a program from this startup list (it will still be available to you on your computer), click once on the name of the program to highlight it, and then click on the – (minus sign) at the bottom of the list.

Run Updates

Many people put off running updates to their operating system or applications because they have heard that occasionally major updates cause more problems than they fix. While this is true for the very early adopters of the major operating system updates, it is not the case for the minor updates which are generally both security fixes and bug repairs.

We strongly recommend that people run minor updates regularly. There is more likely to be an issue if you get behind, and especially if you then try to catch up, than there is if you try to keep up in the first place. We also recommend that people wait a couple weeks before running a major update, to give the early adopters a chance to find the biggest problems and have them fixed. To check your Mac updates:

Click on the Apple icon menu (top left)
Then Click on About this Mac
Finally Click on Software Update
This will show any minor updates, but will not show major steps, especially if you are behind.
Run any applicable updates
If you are behind by major steps, you will need to go to the App Store to download a more recent version of the MacOS.

Check Activity Monitor

If your computer is still slow, it is sometimes useful to find out what is using the processing power. The Activity Monitor application is included on all Macs and will do just this. To check your Mac’s activity:

Click on Finder (Blue face lower left)
Then Click on Applications
Followed by a Click on the Utilities Folder
Double click on the Activity Monitor application

In this case there is nothing using a large percentage of the CPU, but if there were, it might tell you which application was causing your problem.

Delete Browser Extensions

If your main issue is slowness or pop ups when you are using a browser and going online, then the issue might be an errant browser extension. The process is similar with most browsers, so we have two examples here.

In Safari
Click on the word Safari in menu bar (top left)
Click on Preferences

In the preferences window, click on the Extensions icon in the top row.

If any of the extensions are unknown to you, delete them. You can always add them back later if you want them.

In Chrome
Click on the word Chrome in the menu bar (top left)
Click on Preferences

This brings you to the Chrome Preferences. Click on Extensions.

Again, from here you can delete any extensions that you don’t know, and any that you think may be causing problems.

Run Disk Utility

If the issue of speed or errors happens throughout your computing experience, you might want to check your Mac disk drive.

Click on Finder (blue face lower left)
Then Click on Applications
Scroll to the Utilities folder and click on it
Double click on the Disk Utility app
Select Disk – choose the one at the lowest nested level that has the largest blue line. This will be the partition that has most of your data stored on it.
Click on First Aid in the top center of the window.

You will confirm that you want to run First Aid, and you will be warned that you can’t use your computer while this runs.

When it is done, it will show the details of what it did, and whether the disk checks out ok or not.

Uninstall apps

If any of these steps lead you to think that there is an application that is causing your problem or taking up too much space, you can uninstall it.

Click on Finder (Blue face lower left)
Locate and Click on Applications
Find the application in question
Single click to select it and click and drag it to the trash
Empty the trash

Run Malwarebytes

If your work to this point seems to indicate malware, then you should run any antivirus software you have. If you don’t have any, we suggest you download the free 14 day trial of Malwarebytes and run it to check your Mac.