I'm looking for an application that does md5/sha hash check on specific files/folders periodically and store an index file per folder for future verification. I remember such application exist in DOS days, to detect files infected by virus.

The main purpose for this is to detect corrupted copy of backup, as I understand that consumer grade hardware are not 100% error free when doing backup or file transfer from device to device. The hash can also be used to generate a list of changed files for backup.

Most of the software I can find is hash manually.

EDIT: Windows based application, preferably a shell extension which I can right click on a folder and do a checksum/verify all files in that folder. Even better if that can integrate with a backup/sync program like BeyondCopy