during our BlackHat US 2014 talk titled
“Evasion of High-End IPS Devices in the Age of IPv6”,
among others we discussed a Snort preprocessor rule (116:456) which, when
enabled (not the case by default), triggers an alert when an IPv6 datagram with
nine (9) or more IPv6 Extension Headers is used (such a header was used by us to
evade Snort). However, we mentioned that:
Yesterday we (Rafael Schaefer, Enno and me) had the pleasure to deliver together
our talk at BlackHat Europe 2014 named
Evasion of High-End IDPS Devices at the IPv6 Era
(by the way, latest slides can be found
here
and the white paper
here).
In this talk we summarised all the IDPS evasion techniques that we have found so
far. At previous blogposts I had the chance to describe how to evade
Suricata
and
TippingPoint.
In this post I am going to describe some other techniques that can be used to
evade Snort, and its companion commercial version,
Sourcefire. The tool used to evade these IDPS
is – what else
– Chiron.