Is there a Safari plugin to remove mackeeper ads?
Solution 1:
Do you understand how to use the customization features in AdBlock to detect a specific ad and configure AdBlock to block it?
Here are the AdBlock instructions.
Solution 2:
they probably "target" you and you can remove it easily remove it form here https://www.google.com/settings/ads/onweb/ (hit the opt out link)
and here http://www.networkadvertising.org/ (click the opt out red button)