CCleaner as a trojan vehicle?

I was told today by a Microsoft Help Desk Rep that CCleaner is being used as a vehicle for hackers. I have never heard of that possibility and have been using this product on many systems since the original release. I've searched for any indication that the statement is true but find nothing. Anyone at the "home office" know anything or can shed some light on the subject? I depend on CCleaner to keep several Non-Profit's systems runing in good shape.