On-going Internet Emergency and Domain Names
hank at efes.iucc.ac.il
Sat Mar 31 18:38:52 UTC 2007
On Sat, 31 Mar 2007, Mikael Abrahamsson wrote:
> On Sat, 31 Mar 2007, Gadi Evron wrote:
>> In this case, we speak of a problem with DNS, not sendmail, and not bind.
> The argument can be made that you're trying to solve a windows-problem by
> implementing blocking in DNS.
> Next step would be to ask all access providers to block outgoing UDP/53 so
> people can't use open resolvers or machines set up to act as resolvers for
> certain DNS information that the botnets need, as per the same analysis that
> blocking TCP/25 stops spam.
> So what you're trying to do is a pure stop-gap measure that won't scale in
> the long run. Fix the real problem instead of trying to bandaid the symptoms.
IMHO, Windows will always have some 0-day appearing every quarter -
whether it be in XP or Vista. Or it will be in Apache, or it will be in
Sendmail or it will be in some other app. So if taking a 10,000 foot
view, apps will always have 0-day holes that are abused. Nowadays, the
latest vector is fast-flux. I think that closing that vector via fast
closure of a particular domain name is something we should tackle. True,
the baddies will find some other vector. But that doesn't mean we should
ignore this one.
> Mikael Abrahamsson email: swmike at swm.pp.se
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