Astalavista: Offers security directory and related news.
E-Forumz: Forums on hacking and cracking and general computing.
FHCF - Flying Horse Cracking Force: Some background information about the group, member list, and some cracking tutorials.
Hacking and Cracking 3k: Contains tutorials, hacking utilities, and security tools.
K's World: Provides cracking tools and information.
Neworder: Hacking, cracking and security exploits.
Reverse Engineering Team: Contains projects, papers and tools.
Serials 2000: News, discussion, information and help.