Great Circle Associates List-Managers
(July 2002)
 

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Subject: Locking mailing lists to prevent virus distribution
From: JC Dill <inet-list @ vo . cnchost . com>
Date: Thu, 25 Jul 2002 14:39:21 -0700
To: Jim Osborn <jimo @ eskimo . com>,List Managers <List-Managers @ greatcircle . com>
In-reply-to: <20020725191731.GA3355@eskimo.com>
References: <Pine.GSO.4.43.0207131115251.18066-100000@saltmine.radix.net><Pine.GSO.4.43.0207131115251.18066-100000@saltmine.radix.net>

following up on this discussion of lists that allow pix...

On 12:17 PM 7/25/02, Jim Osborn wrote:
 >On Sat, Jul 13, 2002 at 11:22:57AM -0400, Beartooth wrote:
 >> 	I've always excluded pix from the lists I run manually...
 >>
 >> 	Are there any rules of thumb from people's experience as to
 >> how much more bandwidth a list carrying pix eats, as compared to
 >> one that excludes them?
 >
 >I can offer a small anecdotal data point: I run a medium-sized (I
 >suppose) list, about 2K subscribers, maybe 100 of which actively
 >post, maybe 10-40 total articles/day.  I allow gif images, but not
 >jpgs, as gifs are a lot more efficient for the charts that are
 >appropriate for this list.  However, I restrict the article size,
 >including all attachments, to 15K, so they have to make that chart
 >really count!  My list gets relatively few images, maybe one every
 >3-4 days.  I don't allow html at all.
 >
 >I'm a member of another list devoted to the same topic that allows
 >unlimited posting of anything, html, you-name-it.  Some of the jpg
 >charts on that list (that should have been gifs) can run to 400K, and
 >I simply remove them at my ISP so they don't clog my fetchmail queue.
 >I also strip the html off that list as I retrieve it.
 >
 >Even with my various prunings, and the fact that I tend to keep
 >most of the content from my own list (for no good reason :), I
 >find there's at least ten times the bandwidth on the unlimited list.
 >I should mention that that other big list is quite well regulated,
 >on-topic, etc.  The posts tend to run: someone posts a chart and
 >some discussion of it, then ten others chime in with text-only
 >posts.  Neither list is a "pix" list per se; it's just that often
 >a chart is useful to help make the author's point.

I'm on several chatty hobby lists that allow HTML and pics (Yahoo Groups 
hosted lists).  On one list we have had more virus attachments in the past 
few days than we have had actual on-topic attachments.  I've tried several 
times in the past to explain why posting pictures to a list is a bad idea, 
that it leads to problems in the long run (like people automatically 
opening pictures, except for when it's a virus instead of a picture...) and 
been flamed for suggesting people post pictures to a webpage and then post 
the URL instead of attaching the pictures.

So now we have tons of virus infected subscribers who have opened these 
attachments, and the new virus posts are happening more and more and more 
frequently.  I bet this present round of viruses is going to make the list 
admin think twice about this issue.  My guess is that these lists are going 
to not allow attachments at some point before the end of the year, that 
they will HAVE to do this to stop all the virus posts.

A friend runs a distribution list, a monthly newsletter.  Twice now I've 
seen emails (on other discussion lists that many of her members are also 
members of) that say "Jessica has a virus".  No, Jessica doesn't have a 
virus - Klez has picked up her email address and then sent a virus (with 
the Klez forged headers falsely implicating Jessica) to someone that 
happens to also be a subscriber of her newsletter.

Jessica actually uses a password when sending out her newsletter, so for 
now she's safe, none of the present viruses will be able to grab her "from" 
and actually send a virus laden file thru the newsletter distribution 
list.  But....  What happens when someone writes a virus smart enough to 
take a message in your outbox and resend it, with a virus payload?  If she 
has one of the sent newsletters (with the password) in her outbox, and 
catches the virus, then the virus *could* be sent to the entire newsletter 
membership (which is thousands of addresses).  So, for now, they are 
changing the newsletter moderation to use a new address that is approved 
for sending, and to change the allowed address with *each* mailing.

Of course, this is going to cause problems with recipients who filter on 
the "from" unless the newsletter munges the from to some standard address 
(which gets back to the falsely implicated virus emails).

The best thing is to not allow the list to send attachments, but even then, 
if the recipient doesn't remember that this list doesn't ever send 
attachments we are back to the forged virus headers falsely implicating the 
innocent list manager.

I don't know if there's a good solution for this or not.

jc





References:
Indexed By Date Previous: Re: pix on lists : bandwidth?
From: Jim Osborn <jimo@eskimo.com>
Next: Warning -- scripted mass subscribe mailbomb from berlin.de
From: Chuq Von Rospach <chuqui@plaidworks.com>
Indexed By Thread Previous: Re: pix on lists : bandwidth?
From: Jim Osborn <jimo@eskimo.com>
Next: AOL and odd Reply-to
From: Nick Simicich <njs@scifi.squawk.com>

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