How to check if your Mac has a virus
Macs can pick up malware too, just less often and through different vectors. Here is how to tell, and what to do about it.
What Mac malware actually looks like
The classic image of a virus (a program that copies itself and trashes your files) is rare on Mac. What we actually see in the shop is mostly four things: adware that injects pop-ups, browser hijackers that change your search engine, fake support scams that try to scare you into calling a number, and phishing pages that try to steal passwords. None of these are catastrophic, and all of them are fixable.
Signs your Mac may be infected
- Pop-ups and ads showing up where they should not, including on the desktop or in apps that should not show ads.
- Your browser homepage or search engine changed on its own.
- The Mac is suddenly slow, hot, or the fan runs constantly even when you are not doing much.
- Apps or browser extensions you do not remember installing.
- Being redirected to strange websites from links that should go elsewhere.
- Login screens you do not recognize from real macOS dialogs.
The big one to ignore: fake virus warnings
If a website tells you that your Mac is infected and you need to call a number or download a tool, ignore it. These are scams, and they are usually selling either bogus cleanup software or remote-access access that lets a scammer take over your machine. Close the tab. If the tab will not close, force-quit the browser (Apple menu, Force Quit). Real macOS warnings do not appear in browser windows.
What to do
- Do not enter passwords or card details into a pop-up. Close the browser instead.
- Review browser extensions and remove anything you do not recognize. Safari, Chrome, Firefox, and Edge each have an Extensions screen in settings.
- Check Login Items (System Settings, General, Login Items) and turn off anything suspicious.
- Check Applications for apps you did not install.
- Make sure macOS and your apps are up to date.
- Restart and see if the behavior continues.
- Run macOS built-in Malware Removal Tool (it runs automatically; an update may trigger it).
What not to do
- Do not install random cleaner apps. Many are themselves the problem.
- Do not call phone numbers that pop up on screen.
- Do not give remote-access permission to anyone who calls you.
- Do not pay anyone with gift cards. This is always a scam.
If it keeps happening
Bring your Mac in. We can clean it up, reinstall macOS if needed. Most fresh installs are quick. Backing up your data is a paid add-on, so back up anything important first. We treat your data with care and do not browse or copy anything off your machine. Backing up your data is a paid add-on, so back up anything important before you bring it in.
Common questions
Can Macs really get viruses?
Yes, though the Mac threat landscape is different. True viruses (self-replicating malware) are rare on Mac. More common: adware, browser hijackers, fake support pop-ups, and phishing. Macs are not immune; they just face different threats than Windows.
Do I need antivirus on a Mac?
macOS has solid built-in protections (Gatekeeper, XProtect, Malware Removal Tool). For most users, those are enough. If you regularly download from unfamiliar sources, a reputable third-party tool adds a layer. We can recommend one if you ask.
How do I get rid of pop-ups that say my Mac is infected?
Almost always, those are scams from the website you are on, not from your Mac. Close the browser tab (force quit if needed) and do not call any number it shows. We see this almost weekly and the fix is usually quick.
What about fake Apple support calls?
Apple does not cold-call about computer problems. Hang up. If you are worried, look up Apple's real support number yourself and call them directly.
Can you clean up my Mac if it is infected?
Yes. For a real infection our approach is a fresh macOS install rather than traditional virus-scanning software, which we do not find reliable. A clean reinstall is the dependable fix. Usually $99; back up your data first since a reinstall clears the drive.
Want us to take a look?
Bring it in to 196 College St, or send a few details for a quote.