Now THIS is making my morning interesting!

I came into the office today to find a note from my boss showing that a machine with the IP of 192.168.1.200, named "MUJPOLEDNIK" has joined our LAN rather mysteriously. We have no idea what or where this machine is, much less where it came from or how it joined the LAN!

So after having read a few handy AO tutorials, I finally got brave enough to bust out Nmap for some detective work for the first time. So I ran nmap -sS -O -v 192.168.1.200 and got this:

Daylight Time
Host MUJPOLEDNIK (192.168.1.200) appears to be up ... good.
Initiating SYN Stealth Scan against MUJPOLEDNIK (192.168.1.200) at 10:20
Adding open port 135/tcp
Adding open port 139/tcp
Adding open port 6346/tcp
The SYN Stealth Scan took 1 second to scan 1659 ports.
For OSScan assuming that port 135 is open and port 1 is closed and neither are f
irewalled
Interesting ports on MUJPOLEDNIK (192.168.1.200):
(The 1656 ports scanned but not shown below are in state: closed)
PORT STATE SERVICE
135/tcp open msrpc
139/tcp open netbios-ssn
6346/tcp open gnutella
Device type: general purpose
Running: Microsoft Windows 2003/.NET
OS details: Microsoft Windows .NET Enterprise Server (build 3604-3790)
TCP Sequence Prediction: Class=truly random
Difficulty=9999999 (Good luck!)
IPID Sequence Generation: Incremental

Nmap run completed -- 1 IP address (1 host up) scanned in 2.674 seconds
Something is definately VERY fishy. What do you guys think?