Shared folders and C$

Question

With WinXP in a corporate environment, one has to explicitly setup shared folders and define permissions for another user to be able to access them. So for folder XYZ on machine ABC another user could enter \\ABC\XYZ in Windows Explorer (or in the Run box) to open that folder, assuming they have valid credentials on the network. But there is what seems to be a back door, in that that user could also enter \\ABC\C$ to access the root drive of machine ABC--without ever having defined the root drive as a shared folder.

I imagine there is some way to control access to \\ABC\C$ and would like to understand how to do it, in the interests of understanding how secure my workstation really is.

Answer 1

It is not a backdoor as you need to have administrator credentials in order to access this share. If you have administrator credentials for a machine, you can pretty much do what you want anyway!

However, if you want to manually delete or change this share, go in to

"Computer Management" > "System Tools" > "Shared Folders"

or go to the run prompt and type

fsmgmt.msc

and you should be able to see and change it there.

Answer 2

Such access requires administrative credentials on the target machine. Unless the user can already log in as an administrator they cannot access the drive roots unless they are explicitly shared.

Answer 3

Removing administrative shares from within Computer Management will not have a lasting effect. To remove them, follow the information in the article "Remove Administrative Shares" should provide details on how to properly remove them.

That said, I DO NOT recommend doing this - you will disable management abilities that can make things more secure by making it more manageable.