Re: WORM_MIMAIL.A Anyone have any info on what this does yet?

From: kevingeoat_private
Date: Wed Aug 06 2003 - 08:56:30 PDT

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    I just wanted to chime in and say that I have only gotten this worm
    through my 'primary' MX host, which has a pref of 10.  My 'secondary'
    host has a pref of 20.
    
    On Tue, Aug 05, 2003 at 11:54:12PM +0100, Lee Evans wrote:
    > Hi Rohny,
    > 
    > Not to be picky (okay, so I probably am), but when you say you only have
    > a primary (pref 10) and 'pentiary' (pref 50) mail server setup, what do
    > you mean exactly? If you only have two MX records, then the one with a
    > preference of 50 is no less a 'secondary' than if it had a preference of
    > 20, or anything else higher than 10 for that matter. The numbers are not
    > numerically significant, 10 is usually chosen for the primary followed
    > by 20 as secondary, but this is just for general convenience and has
    > simply become something of a habit-come-standard. Your primary MX record
    > could quite easily have a preference of 50, so long as this is the
    > lowest number of any of the MX records. To say that your mail server is
    > a 'pentiary' mail server simply because of the numerical value of its MX
    > preference is incorrect.
    > 
    > It may well be that the virus was deliberately written to choose MX
    > records with a preference of 20, as this is generally a secondary
    > server, as mentioned. In my experience secondary mail servers are in
    > many cases also a secondary consideration, and it may be that the virus
    > writer was hoping to avoid anti-virus systems by avoiding primary email
    > servers.
    > 
    > Regards
    > Lee
    > -- 
    > Lee Evans
    > 
    > > -----Original Message-----
    > > From: Rohny Jotton [mailto:rohnyjottonat_private] 
    > > Sent: 04 August 2003 21:44
    > > To: incidentsat_private
    > > Cc: skidat_private; jshenkat_private
    > > Subject: RE: WORM_MIMAIL.A Anyone have any info on what this does yet?
    > > 
    > > 
    > > This may explain why I haven't seen the virus come knocking 
    > > at our mail 
    > > server (nope, not one). We only have a primary MX (10) set up 
    > > and pentiary 
    > > (50) mail relay upstream which is maintained by our provider.
    > > 
    > > Curious...
    > > 
    > > John
    > > 
    > > -----Original Message-----
    > > From: Jerry Shenk [mailto:jshenkat_private]
    > > Sent: Monday, August 04, 2003 11:43 AM
    > > To: incidentsat_private
    > > Subject: RE: WORM_MIMAIL.A Anyone have any info on what this does yet?
    > > 
    > > Ya know, I thought it was just a coincidence but I saw some 
    > > instances of this going through our mail scanner and it 
    > > seemed like it might have gone through a secondary MX also.  
    > > We hadn't really dug into it but seeing somebody else 
    > > mentioning it does make it look like it may be a design 
    > > issue.  I'm gonna dig into this a little more.
    > > 
    > > -----Original Message-----
    > > From: att13543 [mailto:skidat_private]
    > > Sent: Monday, August 04, 2003 9:54 AM
    > > To: incidentsat_private
    > > Subject: RE: WORM_MIMAIL.A Anyone have any info on what this does yet?
    > > 
    > > 
    > > I'd be interested if anyone can correlate what I've seen:  we 
    > > have 2 MX records, one weighted at 10 (primary) and one at 20 
    > > (secondary).  Of the 200 or so MiMail's we've seen 100% have 
    > > come through our SECONDARY mail server.  Maybe the SMTP 
    > > engine was written poorly, or maybe it was this way on purpose?
    > 
    
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