Hi Robert ,
Adware often comes packaged in installers for other software. Most often, this is because something was downloaded illegally from a torrent or piracy site. Sometimes it is because it has been added to a legit piece of software by an unscrupulous download site. Other times it is because a developer has opted to use an adware-riddled installer, provided with incentives from the adware creator, to distribute their software. It could even be installed through deceit, by pretending to be something that it is not in order to trick the user into installing it. (This last type is usually the only type that is detected as malware by anti-virus software.)
Before you do anything to remove adware, you should back up your computer. There is some risk any time you try removing software like adware, and the risk is larger if you choose to try removing the adware manually if directions aren’t followed precisely. If you don’t already have your computer backed up, go buy yourself an external hard drive around 2 (or more) times larger than the used disk space on your computer’s hard drive, and use Time Machine to back up your computer to that hard drive.
Go through the below link to remove the adware infections manually
Download and run Adware medic to clear the adware infections from the below link
Hope this will help you to sort out the adware problems in your MAC