W2k Security Policy, unknown user

[RyanYarbrough]

I have a small home network consisting of 4 computers, 3 of which are connected wirelessly. I was looking in my local security policy on my W2k box and under some policies such as "Access this computer from network" and "impersonate a client after authentication" there are the normal users listed: administrators, power users, etc. There is also a strange user listed it looks like this: *s-1-5-21-861567501-839522115-1060284298-1104. Does anyone know if this is a Windows 2000 thing, or if it is a hacker who added himself to my users list. Any info is appreciated

Thanks,
Ryan