There is an application out there called 'PC Cleaner' that is a rogue application not to be confused CCleaner. Additionally, the Google Toolbar that is the ride along program with CCleaner may be identified by some avs as a Trojan. Some people think that CCleaner is a Trojan/virus because of this and there are comments all around the web regarding this - its on the web, it must be true! <cough, cough>. I tried to download CCleaner and ESET kept quarantining the file because of the ride along, not because of CCleaner. I contacted customer support and they said I could deselect the ride along before the actual download, so I did, and the second that toolbar was removed from the mix, ESET was once again happy.
As to Microsoft, I have to have CCleaner because their own disk cleanup won't actually clean up my system. CCleaner is a great program, should only be downloaded from the official site, and don't download the tool bar if your av tells you it is a Trojan, because if you force it, it will continue to tell you that it is a Trojan.
