Re: New DDoS attack vector

["Dobbins, Roland" <rdobbins () arbor net>]

On May 20, 2011, at 8:43 PM, ascii wrote:

> the attack you proposed is very stretched and has an extremely low efficiency. 


I believe that the 'attack' is actually backscatter from a targeted attack against the MTAs/antispam systems/recursive 
DNS servers of the organization whose MTAs were inundated with spam in the first place.  It's a layer-7 amplification 
attack, and while the DNS backscatter queries can cause a DoS of the third party's authoritative DNS servers, that's 
merely a byproduct of the actual attack - i.e., collateral damage.

The confusion is caused by a misinterpretation of the observed attack traffic and misanalysis of the attack 
methodology, stemming from misidentification of the actual target of the attack.

Again, there's nothing really new here, and defensive measures exist for both the primary attack vector and the 
backscatter queries which affect the third party's DNS servers.  This isn't a new DDoS attack vector or technique.

-----------------------------------------------------------------------
Roland Dobbins <rdobbins () arbor net> // <http://www.arbornetworks.com>

                The basis of optimism is sheer terror.

                          -- Oscar Wilde

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