RayRay

when im on youtube i get a ad that isn't the typical of youtubes. ibefore i start a video, there is a orange "skipad" button and so i click on the magnifying glass in the lower left hand corner and it brings me to a site "http://overlay.letssearch.com/results.php" and i cant find it in my programs list, i tried running malware bytes in safe mode and while in normal operation. it appears to only be in google CHROMe. so any information on how to remove this would be great. i always tried ad aware but only in normal operation, still, there!!! :(