This is an old revision of the document!
http://www.alienvault.com/open-threat-exchange/projects
http://www.alienvault.com/open-threat-exchange/learning-center
http://www.ossec.net/?page_id=169
http://www.ossec.net/?page_id=165
http://www.ossec.net/files/auscert-2007-dcid.pdf