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Message-ID: <1060748242.2303.205.camel@localhost>
From: r.fulton at auckland.ac.nz (Russell Fulton)
Subject: Blaster: will it spread without tftp?
On Wed, 2003-08-13 at 14:13, Nick FitzGerald wrote:
> "Maarten" <subscriptions@...tsuijker.com> wrote:
>
> > I was wondering about the following scenario:
> <<snip>>
> > - since these other vulnerable systems are using a proxy server to connect
> > to the internet and a firewall prevents all other connections, tftp servers
> > on the Internet can not be accessed
>
> Good up to here, but then...
>
> > - since tftp servers can not be accessed, msblaster.exe can not be
> > downloaded
>
> No.
>
> When the worm connects from its current victim to a new, vulnerable
> host it tells the new victim to TFTP the worm's .EXE from the current
> victim machine where the worm briefly sets up a TFTP thread to serve
> its .EXE.
I can confirm this. We block tftp at the gateway (as well as all the MS
ports 135-139, 445 etc.). An infected laptop was brought on to the
internal network and half an hour later we had 500 infected systems and
a very soggy network.
Note, that those 500 was out of a total of 7500, we had managed to get
the rest patched, another week and we would have only had a handful.
Yes we are now investigating how we can speed up patch deployment ;-)
--
Russell Fulton, Network Security Officer, The University of Auckland,
New Zealand.
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