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RE: Backdoor not recognized by Kaspersky
From: Nick FitzGerald <nick () virus-l demon co uk>
Date: Thu, 04 Mar 2004 13:50:59 +1300

"Aditya, ALD [Aditya Lalit Deshmukh]" wrote:

how about the smtp server simply rejecting mail from spoofed hosts ? as
all the viruses generate spoofed hosts and it is very easy for any smtp
server to do a dns lookup on the sending server, if the hostname / ip
address do not match reject the message.

Because, no matter how much you may not like it, some of us have to use 
spoofing.  It is a designed in feature -- sure a "weakness" by today's 
standards, but not as much of a weakness as the fact that the whole 
Internet as we know it is based on protocols and mechanisms that 
_assume_ physical security and guaranteed locatability of connected 
machines and those with administrative authority over them.  In fact, 
those factors were so deeply ingrained in the original design that I 
doubt anyone involved in spec'ing, designing and implementing what 
became ARPAnet even thought to ask about such issues.

In short, _if_ something was on that network it was _supposed to be 

Who in their right mind would adopt such a system for "the Information 
Super-highway" and encourage business to "get on the net" when it was 
deployed as an open sewer rather than a self-trusting closed network??

Gluing another layer of "machine authentication" into the SMTP protocol 
won't fix any of the fundamental underlying problems that allow spam 
and mass-mailed viruses to aggrieve us so...


Nick FitzGerald

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