I received all these pop up windows after trying to watch some streaming movies on line. One pop up even ask me to call Apple so that they can assist, otherwise they will stop the operation and prevent the com from further damage. I hv ignored all of them but whenever I restart and log onto Safari, these pop up windows come back again. It appears my other browser like Chrome or Firefox is not affected. Perhaps not infected yet. Are all these genuine and shld I rescan by clicking on it. Or shld I do a clean installation. If clean installation is recommended, how it is done (sorry quite noob n this). Am running a Yosemite.