Shared folder permissions

I recently started using Network Scanner and am looking for some clarification. I'm primarily using it to audit shared folder security and I noticed some folders show when the "Everyone" group has access in the Shared Folder Security column, while others are blank even though the folder is open to everyone. I'm running the scan as a domain administrator and I confirmed that account can access the folders and modify permissions, so I don't think it's a permission issue. This may just be expected behavior from it but it seems inconsistent.

Also, Are the "Shared Folder Readers" and "Shared Folders Writers" columns people actively using the shared folders or does that just list everyone with access? It doesn't seem to be showing everyone with access either.

It is supposed to display who can access shared folders (not who is actively using them). This is done by reading NTFS permissions, reading shared folder permissions and then combining them to compute the effective permissions. Unfortunately it does not always work well; for example if NTFS permission reading fails for some reason, there would be no result shown.

I recommend trying this free ShareEnum utility from Microsoft to see if it gives better details for those shares.