Question: how to know if you have a virus mac?
Answer: Adware. Adware are unwanted programs that bombard users with pop-up advertisements. ... 
Trojan horses. Trojan horses can infect both Macs and PCs, and they are often deployed through fake software installers or unsecured updates. ... 
Macro viruses. ... 
Ransomware. ... 
Pop-up ads. ... 
Slowness. ... 
Browser issues.