[X4U] Application Folder - Permissions for unknown user

[John Baltutis]

On 11/20/08, John Erdman <jperdman at gmail.com> wrote:
>
> Sorry about this repost. For some reason my first attempt didn't seem
> to go thru... but some did receive it.
>
> I recently looked at the info on my Applications folder. I noticed
> that besides Myself (Read & Write Access) and Everyone (No Access)
> there are two "users" listed as "(unknown)". The user icons are grayed
> out. The first has Read & Write permissions. The second is listed as
> Read Only.
>
> Even when I access the Sharing & Permissions to make changes, I am
> unable to change either of the unknown's permission levels.
>
> There are no unknown users listed in System Preferences>Accounts.
> Guest accounts are disabled. So far I've been unable to discover the
> source.
>
> I don't like having unknown entities having write access to my
> computer. I suspect these "unknown" users might be related to an Adobe
> or Apple updater but I don't know for sure. I'd at least like to know
> if this is a normal state of affairs or if I ought to be more concerned.
>
> Should I be concerned?
> Who are the Unknown Users?
> How can I find out who/what they are?
> How can/Should I remove them?
>
> OS 10.5.5, 24" iMac 2.16 GHz Intel
> Not on a network.
> Have broadband internet access via phone line DSL. Behind a NAT router.
> I am the only user of this computer.
> Also, I am fairly cautious about what I download or give permissions to.

The unknown user (and group) is a normal one in OS X.

Running this command in the Terminal app, "dscacheutil -q user " reveals:

name: _unknown	uid: 99	gid: 99

Don't muck with it.

Go to <http://discussions.apple.com/> and search for "unknown user". The
resulting posts should point you in the right direction WRT to your query.
Apparently, it's what gets assigned when using the upgrade install option on a
previous Panther or Tiger installation.

On my installation, which was a pristine Leopard OS that I used the Migration
Assistant to transfer from a Tiger installation, my /Applications folder
permissions are: owner me w/R&W, staff w/R&W, and everyone w/R only.