Looks like that your Mac is infected with an adware that injects advertisements into web pages that you are opening in your browser. Important to know that this adware is bundled with and installed by free programs. Follow the steps below to remove pop-up ads in Mac Safari and other potentially unwanted applications.
- open Finder, then Applications. Scroll through the all list and move to Trash any unknown and unused applications. Once completed, empty Trash.
- reset browser’s settings, use the steps http://www.myantispyware.com/2015/11/21/remove-feelbegin-from-mac/#remove-extensions
- download Malwarebytes Anti-malware for Mac from http://www.myantispyware.com/download/malwarebytes-anti-malware-for-mac , scan your mac and remove all malicious files and folders.