Re: [SPAM] [Full-Disclosure] Spam sent via spambots?

[James Riden <j.riden@xxxxxxxxxxxx>]

Hugo van der Kooij <hvdkooij@xxxxxxxxxxxxxxx> writes:

> Sendmail logs also show a significant number of false recipients which
> are known to be part of worms that are by now over 6 months old. Like:
>
> Nov  1 07:16:06 gandalf sendmail[17575]: iA16G3QU017575: ruleset=check_rcpt, 
> arg1=<mary@xxxxxxxxxxxxxxx>, relay=[221.232.95.12], reject=550 5.7.0 
> <mary@xxxxxxxxxxxxxxx>... - REJECTED: KEEP YOUR VIRUS JUNK!; SEE ALSO: 
> http://hvdkooij.xs4all.nl/email.cms
> Nov  1 07:16:07 gandalf sendmail[17575]: iA16G3QU017575: lost input channel 
> from [221.232.95.12] to MTA after rcpt
> Nov  1 07:16:07 gandalf sendmail[17575]: iA16G3QU017575: 
> from=<maria@xxxxxxxxxxx>, size=0, class=0, nrcpts=0, proto=ESMTP, daemon=MTA, 
> relay=[221.232.95.12]
>
> If there are that many worms going around it only shows how easy it is to
> write your own little SMTP engine. Spammers may have deployed similar
> backdoors/trojans/bots/...

A lot of stuff out there will also HELO as <yourdomain>, or the IP
address of your MX. I'm pretty sure it's a worm, because I can't think
how any MTA/MUA could be that broken.

-- 
James Riden / j.riden@xxxxxxxxxxxx / Systems Security Engineer
Information Technology Services, Massey University, NZ.
GPG public key available at: http://www.massey.ac.nz/~jriden/


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