The file bdir.htr is a default IIS files which can give a malicious user a lot of unnecessary information about your file system. Specifically, the bdir.htr script allows the user to browse and create files on hard drive. As this includes critical system files, it is highly possible that the attacker will be able to use this script to escalate privileges and gain 'Administrator' access. Example, http://target/scripts/iisadmin/bdir.htr??c:\
If you do not need these files, then delete them, otherwise use suitable access control lists to ensure that the files are not world-readable.