Yes. MAC computers can get an infection
Back when Apple first hit the market there were no viruses that could infect them because they didn't use the Microsoft .exe executable system. But it didn't take long for those who develop viruses to catch up to Apples file system (UNIX based) which is marked as an executable file in the system metadata. One can remove the .app in a MAC file and it will still work unlike trying to remove .exe in a Windows environment and it won't work. Another fact is that a large number of MAC owners have at least a few infections and do not realize it. This is often attributed to the myth that MACs can't get infected. I have known some MAC owners who work in I.T. that have had infections on their computers but didn't know it until I had to clear their computer of the infection. Even after being shown the infection on their computers many simply state that they didn't think it was possible and that's why they didn't own any anti virus software. If your MAC is not quite operating the way you think it should be, there is a good chance it may have an infection or three.
A MAC BOOK Pro with 85 infections brought Mike's PC Service because it was running slow according to the owner.