IDS evasion - Inundator

IDS/IPS/WAF Evasion & Flooding Tool

inundator is a multi-threaded, queue-driven, IDS evasion tool. Its purpose is to anonymously flood intrusion detection systems (specifically Snort) with traffic designed to trigger false positives via a SOCKS proxy in order to obfuscate a real attack.

inundator would be used whenever you feel there is a significant chance the attack you’re about to perform may be detected by the target’s intrusion detection system. You would launch inundator prior to starting the attack, and continue running it well after you have finished the attack. The hope is that if your attack is detected by the IDS, the alert will be buried among several thousand false positives, thus minimizing the chance of an IDS analyst detecting the real attack.

inundator is full featured, multi-threaded, queue-based, supports multiple targets, and requires the use of a SOCKS proxy for anonymization. Via Tor, inundator is capable of generating around 1000 false positives per minute. Via a high-bandwidth SOCKS proxy, you might be able to generate ten times that amount.

IDS evasion: Inundator Features

ºParses Snort rules files to generate false positive attacks
ºSupport for multiple targets (FQDN, ip addr range, subnet in CIDR format)
ºMulti-threaded
ºQueue-based
ºSOCKS support

Dependencies:

ºNmap
ºPerl (>= 5.10)
ºNet::SOCKS (>=0.03)
ºNet::CIDR (>= 0.11)
ºSnort’s rules files
ºOinkmaster (for keeping Snort rules up to date)
ºTor (If you don’t have a remote SOCKS proxy to exploit.)


When would I use Inundator?

Whenever you feel like it. Seriously. It’s anonymous, so why not watch the world burn?

Example Scenarios:

ºBefore, during, and after a real attack to bury any potential alerts among a flood of false positives.

ºSeriously mess with an IDS analyst and keep an InfoSec department busy for days investigating false positives.

ºTest the effectiveness of an intrusion detection or prevention system. Less alerts means a better product; more alerts means a horrible product.


How does Inundator work?

At a high level, Inundator builds an attack queue, organized by destination port, by parsing the content: and uricontent: fields from Snort’s poorly written pattern-matching rules. Inundator then builds a target queue by performing a port scan to identify open TCP ports on each target provided by the user. Once the queues have been built, Inundator will launch the requested number of worker threads. Each worker thread will select a random target from the target queue, as well as a random open port on the selected target. A random attack for the selected port will then be selected from the attack queue, and this information is used to build a completely innocent packet or request that contains patterns matching typical intrusion detection rules. The crafted attack will then be sent to the target via a SOCKS proxy (we default to Tor’s local proxy.) This procedure is repeated in an infinite loop by each worker thread until the user aborts.

Quite obviously, the actual ruleset used by the target intrusion detection system will play a very large part in whether our crafted attacks trigger a false positive. Inundator will generate an overwhelming number of false positives on systems which use extremely poor pattern matching rules, and little to no false positives on systems which use well written rules, heuristic-based detection, or anomaly-based detection mechanisms.


Downloading and Installing Inundator.

The preferred method of installation for all other .deb-based distributions is via our software repository. This is by far the best and simplest way of installing Inundator and its dependencies.

Add our repository to /etc/apt/sources.list:

deb http://inundator.sourceforge.net/repo/ all/

Next, download and install our GPG key:

wget http://inundator.sourceforge.net/inundator.asc
apt-key add inundator.asc

Then you can automatically pull in Inundator and all its dependencies:

aptitude update
aptitude install inundator

Download Inundator