It is not supposed that since some version ago cclear, even the free versions, did not have ad-ware?
This is preventing ccleaner upgrades since some antiviruses (for example latest eset smart-security) are detecting this as a potential security breach.
All in all you can discard all the antivirus messages an install the ccleaner latest version but, I really think, this is not professional from ccleaner and left much to be desired.
J.