I'm on a mac. What are the odds that I downloaded a virus?

If you have a Mac they only thing that I could say is that it probably is infected with spyware and all that exept viruses since those don't get viruses at all. Also be sure to delete all internet browsing since that may be also the problem. Now if this doesn't work make sure it does not have poor memory. Also scan your computer for malware using malwarebytes antimalware free version www.malwarebytes.org or you can also scan your system using your own antispyware if you have one.