Matthias Apitz guru at
Wed Jan 5 15:59:29 UTC 2011

El día Wednesday, January 05, 2011 a las 10:41:29AM -0500, Robert Fitzpatrick escribió:

> Keep getting calls from our provider at one location that our FreeBSD 
> 8.0-RELEASE server is sending bursts of >1000 spam messages to >70K 
> recipients. Since the first call a few weeks ago, I have MRTG and Mail 
> Statistics graphs setup and see no spikes in traffic. Their last 
> sighting was over the weekend and graphs show a reduction in traffic 
> during that time as expected, again with no spikes in traffic or 
> messages sent/received by our Postfix/Amavisd-maia MTA. All services on 
> that server including SSH, SMTP and mail queue size all monitored by 
> Nagios and have had no alerts from that server.
> Nonetheless, they claim I must have a bot and the mail is not passing 
> through my own SMTP. And I suspect little traffic is needed for the 
> alleged bursts. They have no envelope info. Can someone advise on what 
> port(s) are available for bot detection and/or prevention? In all my 
> years of running FreeBSD as mail gateways, this is the first time I've 
> had this issue.
> --Robert

Check with tcpdump (on another host connected by a HUB, no switch, to
the box) if you can see that port 25 traffic of the NIC of the host;
that would be my 1st check to catch it...

If someone has lifted up your FreeBSD into a VM running on that bot, you
will not see this inside the FreeBSD, I think.

Matthias Apitz
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