The longer you use a computer without performing some basic maintenance, the more sluggish it will become. If you’ve noticed a significant decrease in your computer’s speed lately, there are several things you can do. If you have an adware infection, there are programs designed to scan for and remove these threats.
How to Remove Adware and Cleaning Safari from Mac
Remove any unknown programs from your Applications folder.
Download and install Malwarebytes Anti-Malware for Mac.