Hi malware fighters,
Malware can be grouped into a small number of families of similar code. These can be further subdivided into related sub-families.
You can read about this here: http://www.securityfocus.com/brief/200
More on this from here:
http://www.cs.colby.edu/projects/2004-05/ries.html
and more in-depth info here:
http://nsi.org/Library/Virus/VIRUTOOL.TXT
As malcreants stand on each others shoulders to further their ends, so should we, malware fighters, and how this could benefit us, you can read here: http://www.securityfocus.com/news/11361
polonus