Mac On-Demand Anti-Malware Scanners
macOS includes anti-malware protection, but if you want to run third-party anti-malware, there are many options. Most of them are real-time anti-malware, meaning that they’re constantly running in the background, scanning files as you work with them. If you’d rather run scans only when you choose to, you can use an on-demand scanner.
I’m aware of 3 on-demand Mac malware scanners that are free. These run only on-demand, not in the background.
These free scanners aren’t rated by independent test labs AV-Comparatives or AV-TEST, but they are from respected security software vendors, and those labs do test other security software from those vendors.
Because these run only on-demand, you can use more than one, just don’t run scans simultaneously.
Malwarebytes for Mac runs very quickly; scans sometimes take less than a minute. Malwarebytes says,
The reason is that Malwarebytes is performing what’s called a ‘quick scan.’ Rather than scanning the entire hard drive for files that are known to only be installed in specific locations, it simply looks for those things in those specific locations.
Bitdefender Virus Scanner and Intego VirusBarrier Scanner take much longer to scan. Intego VirusBarrier Scanner is the most CPU-intensive of the 3.
One other free, on-demand anti-malware tool to consider is KnockKnock from Objective-See. It scans locations where persistent software or malware may be installed, and shows what it finds. If the item is an executable binary, KnockKnock automatically queries VirusTotal with a hash of the binary, and displays the detection ratio (if the file is known to VirusTotal).