Some files are denied access by some OSes. So a boot scan could result in no access and the scanning software is dumb about it and gives you a corrupt rather than access denied.
There's also a chance the file system has some issue that needs correcting but as we have no OS noted I can't tell you to use fsck, chkdsk or an Apple boot disc.
When I do a boot scan, often a few files are pulled out and listed as,
"file is corrupted". What does this mean?