Mac cleanup is only done in the case of virus cleanup except for SSD. If you do not know the source of the virus only if you clean your old Mac by cleaning the application is infected, you can remove the virus is infected.
But it is possible to survive when we cannot remove this virus by removing the application. In these cases, we recommend that you consult the virus removal programs. Programs that you can purchase through a license will benefit you completely.
But the programs you download via the browser can do more harm than good. I recommend you to take the original licensed programs, you can do both Mac cleaning and can get rid of viruses.