ZdNetItalia : Files Validator

Check file sizes
Files Validator is a small DOS utility that can check all files (including system and other hidden files) in all directories for any change in size. According to the author, Files Validator can detect a modification as small as one bit without modifying your files in any way. This can help you spot a virus, a file corruption, or tampering (all of which would normally change a file's size). Validate all files in a specified directory or drive, or just validate a single file. And, a file proofreader lets you compare a file with someone who has the same file, without that person actually sending you the file. This update lets you use multiple reference files.