Traffic Talk 3 Posted

My third edition of Traffic Talk, titled Network Security Monitoring: Knowing Your Network has been posted. From the article:

Recently I read an interview with network security pioneer Marcus Ranum, who was asked the following question about network security monitoring: "In your opinion, what is the current weakest link in the network security chain that will need to be dealt with next year and beyond?"

Read my article to see what Marcus wrote and how I responded.

Richard Bejtlich is teaching new classes in DC and Europe in 2009. Register by 1 Jan and 1 Feb, respectively, for the best rates.

Comments

Ken Bradley said…
Hmmm. Marcus comments could not be any more true. Definitely words for any network owner to adhere to.

Know your network.

My recent professional experience with large scale (>100,000 hosts) environments that were plagued with persistent intruders lead me to write a document describing the solution, at least a method of deterrence. I was almost disappointed after putting all my experience together, researching cutting edge technology to address weaknesses and organizing a fabulous deliverable. In the end, 30+ plus pages were basically summed up in one phrase - Get Back to Basics, Security 101.

Well said Marcus. Richard, thanks for getting these thoughts some publicity.
9:47 AM
H. Carvey said…
...what's actually out there, which systems are crucial, which systems hold sensitive data...

ugh, how true. As an incident responder, I see this all the time...lack of network awareness, lack of knowledge as to where sensitive data is processed (or at rest). So far, most folks want to see some kind of new-fangled, high-speed thing as "best practices", because for some reason they just don't get it that it's all about getting back to the basics.

How many times have I worked with a customer who swore to me that the sensitive data on a system was encrypted, only for me to find that either (a) it wasn't, or (b) there was other sensitive data on the system that wasn't encrypted?

The big driver towards all this is now regulatory and legislative requirements. Visa PCI. NCUA. HIPAA. State notification laws. Some of these imply the need for network knowledge and response, others come right out and say it!
8:03 AM
Chris Buechler said…
One discovery method you didn't note is ARP scanning. That will get most firewalled hosts unless they have a modified network stack that won't respond to ARP queries.

Granted that's very difficult in large scale networks since you need a box on each broadcast domain, or to interact with something on each broadcast domain. But when looking at a single subnet, that's something I always like to use as part of a more comprehensive strategy. arping is one such tool
http://www.habets.pp.se/synscan/programs.php?prog=arping
10:13 PM
test said…
A very excellent Traffic Talk, probably my favorite so far. I particularly enjoyed your hypothesis on importance because that is one aspect of using NSM data that I had never really considered before. Thanks.

@Chris Beuchler:
I have used Arpwatch on local network segments with much success and if you are performing NSM and already collecting full-content or session data, it is trivial to run on your sensor.
11:59 PM
Post a Comment

Popular posts from this blog

Zeek in Action Videos

Image
This is a quick note to point blog readers to my Zeek in Action YouTube video series for the Zeek network security monitoring project .  Each video addresses a topic that I think might be of interest to people trying to understand their network using Zeek and adjacent tools and approaches, like Suricata, Wireshark, and so on.  I am especially pleased with Video 6 on monitoring wireless networks . It took me several weeks to research material for this video. I had to buy new hardware and experiment with a Linux distro that I had not used before -- Parrot .  Please like and subscribe, and let me know if there is a topic you think might make a good video.
Read more

MITRE ATT&CK Tactics Are Not Tactics

Image
Just what are "tactics"? Introduction MITRE ATT&CK  is a great resource, but something about it has bothered me since I first heard about it several years ago. It's a minor point, but I wanted to document it in case it confuses anyone else. The MITRE ATT&CK Design and Philosophy document from March 2020 says the following: At a high-level, ATT&CK is a behavioral model that consists of the following core components: • Tactics, denoting short-term, tactical adversary goals during an attack; • Techniques, describing the means by which adversaries achieve tactical goals; • Sub-techniques, describing more specific means by which adversaries achieve tactical goals at a lower level than techniques; and • Documented adversary usage of techniques, their procedures, and other metadata. My concern is with MITRE's definition of "tactics" as "short-term, tactical adversary goals during an attack," which is oddly recursive. The key word in the tacti...
Read more

New Book! The Best of TaoSecurity Blog, Volume 4

Image
  I've completed the TaoSecurity Blog book series . The new book is  The Best of TaoSecurity Blog, Volume 4: Beyond the Blog with Articles, Testimony, and Scholarship .  It's available now for Kindle , and I'm working on the print edition.  I'm running a 50% off promo on Volumes 1-3 on Kindle through midnight 20 April. Take advantage before the prices go back up. I described the new title thus: Go beyond TaoSecurity Blog with this new volume from author Richard Bejtlich. In the first three volumes of the series, Mr. Bejtlich selected and republished the very best entries from 18 years of writing and over 18 million blog views, along with commentaries and additional material.  In this title, Mr. Bejtlich collects material that has not been published elsewhere, including articles that are no longer available or are stored in assorted digital or physical archives. Volume 4 offers early white papers that Mr. Bejtlich wrote as a network defender, either for technica...
Read more