user nobody running find

Hello, I recently installed Suse Pro 9.1 onto my laptop. I have run yast online_update every second day. Today, after booting up, I noticed that performance was slow, so I ran "top" and saw that user "nobody" was running a "find". I killed it immediately. Who is this user? Is this normal, or do I have an intruder? If so, how should I proceed? John