from SpamAssassin developer Henry Stern at this year's CEAS conference:
http://www.ceas.cc/2008/papers/ceas2008-paper-35.pdf
If you're doing SpamAssassin rule development, you really need to read
this.
A Survey of Modern Spam Tools
Abstract
Over the past 5 years, spam sending technology has improved dramatically.
Static messages sent opportunistically through misconfigured hosts have
evolved into dynamically generated, subtly obfuscated messages sent on a
massive scale by special purpose malware. We present a survey of three
generations of the most popular spam sending tools, focusing on how they
have improved over time. The paper conclude with a case study of a modern
spam campaign, showing how the spammer has used randomization to make
their messages more difficult to detect by content filters.
Great research into Send-Safe, Dark Mailer and Reactor Mailer/Srizbi.
--j.
