It appears that Microsoft Security Essentials dislikes the eBay stuff you offer in CCleaner. I understand that this may be a source of income for you and that is okay by me.
But could I PLEASE, please have a chance to buy a "license" for a version without Yabector?
Piriform doesn't offer any ebay stuff in it's install of CCleaner, only the Yahoo Toolbar, which you have the option to uncheck. And CCleaner is free to all.
It sounds like you've downloaded a rogue version, or a program with a similar name.