Unusual warning message when copying an IOS .bin file

[per_2]

I'm copying an IOS .bin file from my hard drive to my thumb drive so that I can carry it into our lab to do some testing.  I get a screen pop with Title Bar: "Confirm Stream Loss". 

The warning says: The file 'xyz.bin' has extra information attached to it that might be lost if you continue copying.  The contents of the file will not be affected.  Information that might be lost includes:   (and then a field below lists)

:PG$Secure$DATA

Has anyone ever seen this, or know what this value comes from or represents?

Thank you.

Per

[Gregory Snipes]

What file system are you running on your thumb drive? NTFS allows some file attributes that are not supported by other file systems like FAT32.

[per_2]

It's running FAT32, and I'm pretty certain that moving the file from NTFS to FAT32 is why the value is being stripped away.  I'm curious about what the value is and what purpose it serves.

[Gregory Snipes · Accepted solution]

I am no NTFS guru, but the NTFS wikipedia page states that "$secure" is an ACL database and that "$data" is just a default attribute.

[per_2]

Very interesting, and great reference.  Thank you, Gregory!

Per