If you want to check the well know site download 3K Editor's Review about File Renamer, reviewed by Gary Oldwood, just follow the link above. It's quite a long one, and a nice one too - if I can say so myself..

Also, they test all hosted software for virus by using five different antivirus software to go trough it and the Antivirus Report can be found here: File Renamer antivirus report

Just another layer of safety to keep us all less worried, thanks to their work!