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Date:      Fri, 30 Jul 2004 18:22:00 -0600 (MDT)
From:      Warren Block <wblock@wonkity.com>
To:        Tim Schutt <tim@square1consulting.com>
Cc:        freebsd-questions@freebsd.org
Subject:   Re: amavisd/clamav Virus Recipient email notification template woes
Message-ID:  <20040730175822.W77732@wonkity.com>
In-Reply-To: <1F94DE30-E269-11D8-8A9E-000A27B47720@square1consulting.com>
References:  <12abd8c2040730104259ea346e@mail.gmail.com> <20040730160947.4fdbe0dd.wmoran@potentialtech.com> <1F94DE30-E269-11D8-8A9E-000A27B47720@square1consulting.com>

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On Fri, 30 Jul 2004, Tim Schutt wrote:

> On Jul 30, 2004, at 4:09 PM, Bill Moran wrote:

>> If you're going to send notification, there is only one _proper_ way 
>> to do it: analyze the Received: headers and find out where the virus 
>> _really_ originated, then contact the abuse@ address for that domain 
>> with the message.

> I completely understand where you are coming from, and I am only intending on 
> notifying the intended recipient of the email, not the "sender" for the very 
> reason that you note. If it was just me, I would can the message and be done 
> with it. However, I am in the midst of marketing this service to some highly 
> security conscious people so I would like the reinforcement of the 
> notifications for their piece of mind and a little customer-stroking 
> reminding them how great the service is. :-)

[Format recovered--please don't top-post.  It makes responding to your 
messages difficult and time-consuming, to the point that many people 
won't bother.]

"Virus detected" messages are generally abusive.  Here are some problems 
I've experienced on the receiving end of antivirus notification 
messages:

* Sent to the forged From address.  We'll skip the issue of a virus
   checker that trusts any content in a virus-generated message;
   what about long CC: and BCC: lists?

* Sent to the intended victim--"Hey, you almost got away without being
   harassed, but we wanted to brag about our antivirus system."

* Some include "this message guaranteed virus-free" text.  It's like the
   sender is saying "please sue me".

* Sent outside the detecting system's domains, spreading the damage.
   If you must send notifications, send them only to those systems you
   control, and where you are responsible to your users.

* Antivirus software forges "postmaster@victim'sdomain" into the From:
   line.  Senders of these messages get a 550 reject for all further
   mail.

* Some notifications include the virus.  Yes, there are actual
   "antivirus" programs out there that are dumb enough to do this.

Bearing that in mind, here's a suggestion for clamav flags:

clamav_milter_flags="--quiet --local --outgoing --max-children=50 --dont-log-clean --noxheader --outgoing"

-Warren Block * Rapid City, South Dakota USA



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