- Attrition.org - A collection of internet and computer security resources.
- Crewl Underground Madness - Belgian group specialized in computer and network (in)security, hacking, coding and phreaking.
- Cult of the Dead Cow - Offers weblog, team background, tools and BackOrifice downloads, and news archive.
- Eleventh Alliance - Offers details regarding select viruses, overflow and security exploits, bios tools, and crytography. Also features book reviews on assembly programming and computer security.
- enZo - Coding group. Offer hacking tools and vulnerability exploits.
- HackHull - Group of hackers in the United Kingdom. Information about meetings, projects, and links to personal pages.
- HATE (Hackers Against Tyranny Everywhere) - Anarchy, HAcking, Phreaking files for newbies.
- Moloch Industries - A New York hacker group.
- Nomad Mobile Research Centre - Hacker lab engaged in vulnerabilities research. Security papers, full disclosure advisories and current projects. Also features a FAQ on hacking techniques.
- Progenic Security - Security advice and exploits.
- Twentythreedotorg - SoCal's hacking group. Canadian free since 1999.
- Xfocus - Organization dedicated to the research and demonstration of vulnerabilities in network services and communication security. Offers papers, security tools, exploit code, advisories and a discussion forum.
