Internetworkers: http://www.ibiblio.org/internetworkers/

["Josep L. Guallar-Esteve" <jlguallar AT maduixa.net>]

El dia Dijous 20 Juny 2002 03:05, no tenies res mes que fer i vas i m'envies 
aquest e-mail:
> Talk about makin' a body real mad.... It's happened again! I'm getting a
> slew of failed mail notifications because some spam [nasty] has
> appropriated my e-mail address! I reported it to the Mindspring/Earthlink
> abuse desk, but don't know if they can/will do anything (I sent a copy of
> the full text of one of the 30 failure notifications).... Anyone have any
> further ideas? I do have the failure notifications, some of which include
> an attachment of the filthy spam....


Are you sure is someone taking over your identity for spam pouropses?

The Klez virus has a behavious that, first, made me think that someone hasd 
taken over my email address. Then, I learnt some more about Klez. Now I know 
that it was the Klez virus.

How the Klez virus work?

First, infects someone

Then, checks for e-mail addresses in the addressbooks, cached-webpages, sent 
messages, received messages, newsgroup messages (if you are into usenet)...

Now, the virus decides to use one of those collected email addresses as the 
forged "From" field, to make more difficult to detect the infected machine.

The last step is the "reproduction": the virus sends itself to all the 
collected e-mail addresse, using the "From" (and, I think, "Retrun-To") 
field(s) forged so they point to someoneelses's adress.

So, when an infected email bounces, it bounces to an uninfected, unsuspecting 
email address (the one used in the "From" field).

Of course, using the "Sender-IP" field you can verify that it was not you who 
sent the email. 

With some triangulation, SamSpade and a few friends, I was able to get to one 
of my "Windows-friends" infected with the Klez viirus that was using my 
e-mail address in the "From:" field.

Hope that this is your case.



Salut,
Josep
-- 
Josep L. Guallar-Esteve, QA-Test Engineer, Red Hat, Inc.
http://www.ibiblio.org/sinner/