"Macs don't get viruses" is one of the most persistent myths in computing. While macOS does have stronger built-in protections than Windows, Macs absolutely can and do get malware — especially adware, browser hijackers, and potentially unwanted programs (PUPs).
Here are the 7 warning signs our technicians look for during a Mac malware assessment.
1. Your Browser Has a New Homepage You Didn't Set
If Safari or Chrome suddenly opens to a search engine you've never heard of (Bing doesn't count — Microsoft pushes that legitimately), something changed your browser settings. This is classic adware behavior. Check Safari → Settings → General → Homepage and Chrome → Settings → On Startup.
2. Pop-ups Telling You Your Mac Is Infected
Ironic, right? The most common Mac malware is the "your Mac is infected" pop-up. Legitimate Apple warnings never appear in your browser. If you see a browser tab claiming your Mac has viruses and you need to call a number or download a "cleaner" — close the tab immediately. Don't call the number.
3. New Browser Extensions You Didn't Install
Check Safari → Settings → Extensions. If you see extensions you don't recognize, remove them. Common culprits include "SearchHelper," "SafeFinder," and anything with "toolbar" in the name.
4. Your Mac Is Suddenly Slow
Open Activity Monitor (Spotlight → type "Activity Monitor"). Sort by CPU usage. If a process you don't recognize is consuming 30%+ of your CPU consistently, it could be crypto-mining malware or adware.
Legitimate Apple processes have recognizable names (kernel_task, WindowServer, mds_stores). If you see something random like "mshelper" or "xmrig" — that's malware.
5. Your Search Results Look Different
If Google searches are returning results with extra ads at the top that look slightly off, or if clicking a link redirects you through a different domain first, you have a browser hijacker. This is one of the sneakier forms of Mac malware because the search page looks normal.
6. Apps Are Opening That You Didn't Launch
If random apps are launching on their own — especially browsers navigating to unfamiliar sites — check your Login Items (System Settings → General → Login Items) and Launch Agents folder:
~/Library/LaunchAgents//Library/LaunchAgents//Library/LaunchDaemons/
Any .plist files from companies you don't recognize should be investigated.
7. Your Firewall or Gatekeeper Has Been Disabled
Check System Settings → Privacy & Security. If "Allow apps downloaded from" is set to "Anywhere" and you didn't change it, something did. Same for the Firewall toggle — it should be on.
What to Do If You See These Signs
- Don't download a random "cleaner" app — many of them are adware themselves
- Don't pay for phone support from a pop-up — it's always a scam
- Do run Malwarebytes for Mac (free version) — it catches most adware
- Do check your Login Items and browser extensions — remove anything unfamiliar
- Do call us if you're unsure — our free diagnosis takes 10 minutes and we'll tell you exactly what's going on
Mac malware is rarely catastrophic — it's mostly annoying. But it slows your machine, invades your privacy, and gets worse if ignored. A $99 remote cleanup gets your Mac back to clean in under an hour.