Ads keep appearing every time I click anything on safari. How do I get rid of it?

Question

when I use Safari every time I click an advert appears in a new window - fashion, mackeeper, cloud, russian models, you name it it appears. How do I stop it?
And when I am working some words get highlighted, even in my bank account, and when I hover and ad appears, mad apparently by Deal Top. How do I get rid of that?

Answer 1

This can happen if adware is installed without your knowledge.
1. Use  free  AdwareMedic to remove adware
    http://www.adwaremedic.com/index.php
   Install , open,  and run it by clicking “Scan for Adware” button   to remove adware.
   Once done, quit AdwareMedic.
             or
   Remove the adware manually by following the “HowTo” from Apple.
   http://support.apple.com/en-us/HT203987
2. Safari > Preferences > Extensions
    Turn those off and relaunch Safari.
    Turn those on one by one and test.
3. Safari > Preferences >  Search > Search Engine :
    Select your preferred   search engine.