like tony said, what kind of services is it running, either case, FIRST thing i would do is to disconnect from the network, then use the tool above mentioned by the senior members to identify them if you really want to know. of course it could be a spook, so for me to say rebuild if there isn't anything important could be just waste of time. try a program like fport to see what or where it's sending out it's echo. good luck.

-w0rm3y