To run an antivirus scan on a Mac, follow these steps:

1. Make sure you have an antivirus program installed on your Mac. If you do not have an antivirus program installed, you can download and install one from the Mac App Store or from a reputable website.
2. Open the antivirus program on your Mac.
3. In the main menu of the antivirus program, select the option to run a scan. This option may be labelled as «Scan,» «Full Scan,» or something similar.
4. Depending on the antivirus program you are using, you may be prompted to select the type of scan you want to run. Most antivirus programs offer different scan options, such as a quick scan, a full scan, or a custom scan. Select the type of scan you want to run, and then click «Start» or «Scan Now» to begin the scan.
5. The antivirus program will now start scanning your Mac for viruses and other malware. This may take several minutes or longer, depending on the size of your hard drive and the type of scan you are running.
6. If the antivirus program detects any viruses or other malware on your Mac, it will display a list of the items it has found. Review the list, and then select the option to remove the detected items. This will remove the malware from your Mac, and help to protect your computer from future infections.
7. Once the scan is complete and any detected malware has been removed, you can close the antivirus program and continue using your Mac as normal.

Note: It is important to keep your antivirus program up to date to ensure that it can protect your Mac against the latest viruses and other malware. Most antivirus programs will automatically check for updates and prompt you to install them when they are available.