I was recently visiting my parents when I received the dreaded question: I think my Mac is infected with a virus, but I thought Macs weren’t infected with viruses? They were obviously a little worried and somewhat embarrassed that they might have let something happen to their Mac.
First things first: yes, your Mac can get a virus, although this is quite rare. After all, there are far fewer viruses in the wild to attack macOS than Windows, and far more PCs than Macs in the world. But there are Mac attacks in the wild, and many of them come from a web browser.
There are many ways to scan your Mac for viruses and protect it from incoming attacks. Apple even has its own built-in antivirus technology called XProtect, which constantly scans for known malware. But even with all this protection, things can happen.
However, if you receive messages on your Mac warning you of a critical virus with scary emoji, it’s probably not a virus. Chances are it’s just an app notification masquerading as a critical system alert.
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Here is what happened. While browsing with Safari, my parents clicked on an ad or received a pop-up that took them to update-mac.com. When they arrived there, another box asked them if they wanted to receive notifications from the site. In a fit of click-to-escape, they clicked “Allow” when asked if they wanted to receive notifications. This told Safari that it was OK to spam them with scary alerts.
Fortunately, there is a simple solution: go to the Websites tab in Safari Settings in the menu bar and deny the site permission to send alerts under the Notifications
Apple also has a malware tracking tool built into macOS called XProtect and is constantly updating the operating system to patch any known vulnerabilities. To limit any further damage, you can download an antivirus application, which will protect you from inadvertently installing something malicious and help you get rid of it if anything gets through. But for everything else, check your Safari notifications first.