Here's the solution!
Here are two helpful links that provide guides to the removal of some popular forms of adware out there...

Here's the (free) tool that we use every day in our office: 
https://www.malwarebytes.org/antimalware/

If that tool doesn't solve your problem, check this resource: 
http://www.thesafemac.com/arg-identification/ 


  
If neither one of those links are of help: don't hesitate to come by our office for some help!