Using tools such as lsof or truss, if you have them installed.
Examine the calls, perhaps some file is missing and program runs continuously in loops or similar issues (could explain the large %sys usage)
Also issue a find to perhaps to locate from which script is that spawned as rbatte suggested.
Something in the line of :
If you get a match, examine that script for possibility to disable that and what that is actually.
Perhaps i can offer more assistance in couple of days when i get to hpux box.