F-Secure behaviour confirmed; when I tried to install the latest CCleaner I got that warning. After a little wondering I disabled the anti-virus software first after having checked the installer package with no reaction. Then after CCleaner install I checked the system with no reaction, so it's the first time I got a false positive with F-Secure. But what have you changed to mislead F-Secure - or perhaps F-Secure definitions have changed to give that false positive. I have had CCleaner installed perhaps 2 years as well as F-Secure but it's the first time I got that warning. And I regard both softwares as highly recommended!