Viruses and Malware / Remove from a macOS computer

Objective

• To provide instruction on running a scan and removing viruses and malware from a Mac (macOS) computer

Environment

• 10684: DHCP
• Personally Owned Computers
  • macOS

Cause

• According to this Malwarebytes article, there has been a 230 percent increase in Mac malware since July 2016 
• While macOS computers are rarely infected by viruses and malware, they can pass viruses and malware to PCs

Resolution

1. Scan your Mac
   1. Follow this link to download Sophos, a free Mac antivirus software
   2. Open your Applications folder and click Sophos Home
   3. In the Full Scan field, click the Scan Now button to scan and remove threats from your computer
   4. Save the scan logs as proof of removal
      • You must present scan logs as proof of removal so that your access to the network can be restored 
2. Remove malicious software on your Mac
   1. Quit the web browser by pressing Command+Q on your keyboard,
      • Or right-click on the browser icon and choose Quit
   2. Open your Downloads folder
   3. Drag any install files or files that you don't recognise into the Trash
   4. Right-click on the Trash icon and choose Empty Trash
3. Remove installed malware on your Mac
   1. If the suspicious app is open, note the name of the app
   2. Move or close the app window
   3. Press Command+Shift+U on your keyboard to open the Utilities folder
   4. Open Activity Monitor
   5. Choose All Processes
   6. Look for the name of the suspicious app or an app that you don't recognise
   7. Click Quit Process
   8. Open the Applications folder and locate the suspicious app
   9. Drag the unwanted app to the Trash
   10. Right-click on the Trash icon and choose Empty Trash
4. Keep your Mac safe from malware
   1. Keep your macOS current
      • Open the App Store app and click Update All
   2. Turn on automatic updates
      1. Open System Preferences and click App Store 
      2. Select Automatically Check for Updates
      3. Make sure both Install macOS Updates and Install System Data Files and Security Updates are also both selected
   3. Make sure your Mac only allows apps from trusted developers
      1. Open System Preferences and click Security and Privacy
      2. Click General 
      3. Check the option under Allow Apps Download From
         • It should be set to Mac App Store or Mac App Store and Identified Developers
           • If it is set to Anywhere, click on the Lock icon, enter your password, and change it
   4. Get your software from the Mac App Store or from developers you know and trust
   5. Install Mac antivirus software

Notes

• Source: Macworld: How to remove Mac viruses for free
• Also See How to remove Malware from Mac