Catapults and grappling hooks: The tools and techniques of information warfare

For years, "hackers" have broken into computer systems, and now an entire industry is dedicated to computer network security. Both hackers and computer security professionals have developed software tools for either breaking into systems or identifying potential security problems within computer networks. This software can be found on compromised systems as well as within the toolkits of legitimate "tiger" teams that operate with the consent of the network owners. This paper describes some of the current techniques and tools employed by the hacker underground in breaching the security of networked computers, focusing primarily on UNIX(R)-based hosts connected to TCP/IP networks.