Worm? Trojan? Attack tool? Network administrators and security experts continue to search for the cause of an increasing amount of odd data that has been detected on the Internet. Security software firm Internet Security Systems (ISS) on Thursday declared victory, saying that a new hacker tool that scans for paths into public networks was responsible. But many other security professionals--including those at Intrusec, the company that originally tracked down the hard-to-find code--believe that ISS jumped the gun. The real culprit likely is still out there, said David J. Meltzer, founder and chief technology officer of Roswell, Ga.-based Intrusec. "It is...