Customer Reviews

The Tao of Network Security Monitoring: Beyond Intrusion Detection

5 star:		(20)
4 star:		(2)
3 star:		(0)
2 star:		(1)
1 star:		(0)

 

 

Here is a really cool security book, that made me lose half a nigh sleep when I first got it. Richard Bejtlich "Tao of Network Security Monitoring" ("Tao of NSM") covers the process, tools and analysis techniques for monitoring your network using intrusion detection, session data, traffic statistical information and other data. Here are some of the book highlights.

The book starts from a really exciting and fun background on security, risk and the need to monitor networks and systems. Topics such as the classic "threat x vulnerability x value = risk" formula to threat modeling and limitation of attack prevention technologies are included. A nice thing on the process side is the "assess -> protect -> detect -> respond" loop, that defines a security process for an organization on a high level. Threat analysis material seems to have military origin, but is enlightening for other types of organizations as well.

NSM is introduced as being 'beyond IDS' with some coverage on why IDS deployments fail and what else is needed (NSM process and tools, that is).

A great and rarely appreciated idea expressed in the book is that the intruders are often smarter than defenders. It presents a stark contrast to all this "staying ahead of the hackers", which makes no sense in many cases as the attackers are in fact far ahead. NSM approach will indeed work against the advanced attackers, albeit a high resource cost to the defending organization. Such 'worst case' scenario preparations are extremely rare in other security books. Detecting such intruder is covered during their five phases of compromise (from reconnaissance to using/abusing the system).

Another gem is an idea of a "defensible network"; not 'secure' or 'protected', but defensible. 'Defensible network' can be watched, is configured to limit possible intruder actions, can be kept up to date and runs only the minimum necessary services, that assures that if bad things happen there, they can be handled effectively.

I also liked how the tools are covered in the book. It is not a tool manual rephrased, but rather the whole tool use context related to the rest of the NSM. While the paradigm 'products perform collection, people perform analysis' might be faulty as the products are getting smarter, having training analysts still is one of the best investments in security. On the process side, the book covers complete analyst training. People are indeed the critical component of NSM, since most of the decision-making relies on trained analysts and their investigation, classification and escalation of alerts.

A chapter on netflow and other types of session/connectivity data presents considerable interest to those monitoring networks. Example case studies show how such data helped identify intrusion action that did not directly product IDS alerts. Same applies to traffic visualization and statistical tools that enrich the IDS data and can sometimes provide early anomaly indications as well.

Of course, NSM event-driven analysis is centered on Sguil - a new GUI frontend to NIDS, session and other context data, facilitating easy and effective event classification and escalation (if needed).

Emergency NSM vs ongoing monitoring NSM procedures are also covered in the book. Even if the organization does not maintain an ongoing security monitoring program, it can still benefit from NSM that is deployed after a suspected intrusion.

Attacks against NSM processes and technologies also fill dedicated section. Such attacks include intruder tools as well as attacks against the human (such overwhelming the analysts) and process components of the NSM.

Overall, the book is a required reading for any security professional and those wishing to become one. It helps to broaden the horizons of seasoned professionals as well as educate the beginners in monitoring techniques. While value of NSM as an approach can be debated in modern organizations where tuned sensors and skilled analysts are an exception rather than the rule, the book is a superb security resource even for those who do not choose to implement NSM at the moment.

Anton Chuvakin, Ph.D., GCIA, GCIH is a Senior Security Analyst with a major security information management company. He is the author of the book "Security Warrior" (O'Reilly, 2004) and a contributor to "Known Your Enemy II (AWL, 2004). His areas of infosec expertise include intrusion detection, UNIX security, forensics, honeypots, etc. In his spare time, he maintains his security portal http://www.info-secure.org

Richard Bejtlich hits one out of the park with this terrific book. In one stroke, he moves the art and science of intrusion detection out of the little leagues and into the majors. If you've already run through articles and books with advice like "just load SNORT and start tuning", this book will shift you to an all-star level in which thousands of machines across enterprise networks can be monitored and protected.

Network security monitoring (NSM) is the discipline of collecting and interpreting detailed network traffic to find and foil attackers. Although it may seem like Intrusion Detection (and IDSs), the relationship between IDSs and NSM is like that between Bonzo the chimp and King Kong. Almost anybody could handle a chimp for a few hours - or you'd think so from watching the movies - but bringing King Kong into your neighborhood means you really have to know what you're doing. He'll take a lot of feeding and special care. On the other hand, he does much more than Bonzo can to protect your assets. Network security monitoring is the King Kong of intrusion detection techniques.

The author presents detailed information on a large variety of network traffic capture and analysis tools, techniques, and topologies. Nearly all are public domain and open source. The few exceptions are tools specialized for industry-dominating Cisco and its proprietary formats and protocols. A few hours on the Internet with this book in hand can give you just about all the tools needed to follow his examples and to build your own network security monitoring environment.

Basic network activity capture is addressed through packages like the fundamental libpcap libraries, and the tools Tcpdump, Tethereal, Ethereal, and Snort (in its packet-capture mode). Tools for converting, combining, and subsetting captured data receive equal attention, with working examples based on editcap, mergecap, tcpslice, the Berkeley packet filter (BPF) language, tcpflow, ngrep and others. GUI tools are touched on as well, including EtherApe and NetDude. For the more advanced topic of session data or "flow" capture (using the Cisco NetFlow data format), there are equally-detailed discussions of the Flow-Tools package, the Argus analysis tools, tcptrace, and others.

Statistical reporting and analysis gets a chapter, while alert processing (the classic IDS functions of Snort) get two, covering Bro, Prelude, and Sguil. (Although the book mentions Snort briefly, it assumes you have access to sufficient information to load and use Snort without assistance.) Much of the remainder of the book addresses the practical issues of installing, operating, and administering network security monitoring in the environment of an enterprise or Internet service provider.

It's refreshing that the software tools are not just mentioned, they are shown in operation in several scenarios each. The reader can see why they are important to the craft of network security monitoring, and can follow the examples on their own computer once the tools are installed. The author's style is not quite a tutorial, but it's easy to learn from him.

Most striking, perhaps, is the author's focus on completely professional installation and operation of this sensitive security function. He talks about network topologies and their effect on sensor placement. He provides alternative designs for the collection of data and for its analysis, usually on separate workstations. His stated experience is on large and very busy networks, so he addresses some difficult techniques (such as merging data from separate sensors to simulate a real-time data flow on a single machine) that are valuable and often mandatory in distributed enterprises. At the same time, his advice supports smaller networks and more limited security goals - you just have to pick and choose the items you need from the very large smorgasbord he presents.

So impressive is the technical detail, you could forgive it for being less than polished. But the writer is not just competent, he is entertaining and enjoyable to read. Between Bejtlich's skills and those of the editors, this book has no bizarre jumps of topic, no dead space, none of the clanging infelicities and groaners that haunt most of the technical books we read each month.

We should be clear about this book's audience: it is not an executive overview or a manager's guide. This is a manual for practitioners. It is pitched toward those who are comfortable purging a desktop machine and converting it into a single-purpose network sensor, those who can download source code and compile tools in multiple operating systems, those who will find it worthwhile to put their hands on and their hearts into a challenging and open-ended endeavor. But for those whom it suits, this will be an indispensable guide, the complete play-book of a fascinating new security specialty.

This is a great book. With most geek books, I browse and grab what I need. With this one, I even read the apendices!

At first, the author's tone put me off. He spends the introductory chapters talking about the "Way" of Network Security Monitoring, (capitalized) and how it's much better than other approaches. It felt a little like, "My Burping Crane Kung-Fu will defeat your Shining Fist techniques!" I really didn't see much difference between what he was talking about and other approaches. I admit to being much newer to this discipline than the author, and he has an impressive appendix on the intellectual history of intrusion detection (uncapitalized). So it may be that the lessons he advocates have already been internalized; my exposure may have been to a field that has already moved up to his standard. But I have a hard time imagining that intrusion analysts have ever been satisfied with a single approach with no correlation. As I understand what he means by upper-case NSM, it's basically the efficient use of multiple techniques to detect intrusions. I can't see trying to argue the contrary position.

Ah, but then we get to the good stuff. He goes through the major types of indicators and the means of reviewing them. He covers the use of a number of important tools, but doesn't rehash what is better covered elsewhere. For example, he doesn't bother covering Snort, because there are plenty of books on Snort already. If you are reading the book, it's almost a certainty that you are familiar with Snort. Good call to skip over that. Instead, he covers some other tools that might be useful in the same area. He also refers to tons of other books. I made a lengthy wish-list based on his recommendations and they've been good. (He also reviews exhaustively here on Amazon). So this book is like the first stone in an avalanche- it triggers the acquisition of many other books.

The book provided many 'light bulb' moments. For example, he talks about giving up on source-based focus. In a world where a DDoS attack is currently using 23,000 separate bots, we may exhaust our resources tracking low-value drones. So focus on the targets they are after: light-bulb! In spite of my earlier resistance, I was soon going through it as eagerly as I did with the Patrick O'Brian Aubrey/Maturin novels. It's fun to read such clear, authoritative writing.

One quibble - he trashes the SANS intrusion detection course, which I took and thought was terrific. He has taught the class, and considered the course material out of date. Maybe they have updated, but his book didn't contradict anything in the course as I took it 1.5 years ago.

As commercial websites and networks get built out, some companies find that their network becomes the nervous system of the organisation. The ubiquity of email and browsing, and the storage of much corporate information on a network, has led to a vital need to defend it.

The good news, in part, as pointed out by Bejtlich, is that you, the sysadmin, have available a very powerful set of free, open source tools, to scrutinise the network for anomalies. Tcpdump, Tethereal, Ethereal, Snort, Editcap, Mergecop, Tcpslice, etc. All free and supported by communities of developers. But these are not trivial to use. For example, Ethereal and Snort each have entire books devoted to them. Not surprisingly then, a large portion of this book discusses using the many tools. You do not necessarily need to use all of them. But as a sysadmin, you need to be generally aware of the different capabilities of the major tools, and how to best use them. Some explanations also include screen captures from their UIs, to give you a better idea of their operation.

But the book is more than just a collection of tool explanations. Bejtlich also promotes an overarching coherent approach to network security monitoring, that rises above the operational details of any tool. Much more qualitative than the specific details of using a given tool. But ultimately, this approach may be the most enduring value of the book.

A problem with the approach many people take to network and security monitoring is that they expect it to be plug and play. Install the software and then stop attackers in their tracks. If only it was so easy. But one can't simply install monitoring software or an IDS, collect data and expect it all to correlate and correct itself.

The beauty of The Tao of Network Security Monitoring : Beyond Intrusion Detection is that it shows how network monitoring requires a strong discipline to truly have an effect on security.

The book is written for the person; primarily a system administrator or security engineer whom truly wants to use an IDS to manage and secure their network. This is not an introductory text, rather it is written for someone not scared of downloading and compiling code. If you are looking for an intro to IDS usage, this is not the book for you. This is a book about someone who has an IDS, and needs to find a way to use it and tune it for maximum usage.

The book has a near endless supply of network traffic capture and analysis tools, techniques and network topologies. Beyond simply providing a list of software tools, the book shows how to install and configure a variety of these tools. Rather than wasting pages and screen shots detailing how to download and install the software mentioned; the book shows how to use the tool in the context or Tao of security monitoring.

In addition, the author emphasizes the point that the people are a crucial aspect of effective network monitoring. The ultimate success of any IDS is directly tied to the analyst behind the console. They are the ones making the decision on how to respond to an incident, and if they are not appropriately trained, all of the hardware and software will only provide a fraction of it potential.

With that, The Tao of Network Security Monitoring should be considered required reading for anyone using an IDS or responsible for its use. If you have staff using an IDS, ensure that they have read The Tao of Network Security Monitoring as it will educate them in truly understanding how to monitor a network.

I'm not sure why, but my first review of this book was not posted. However, I feel that this book definitely warrants a second attempt. The Tao of Network Security is a definite must have for anyone serious about the field of network security. While the book is heavily BSD biased, the tools illustrated throughout the book are free and can be compiled on just about any platform. The author draws from his years of experience as a network security analyst for the Air Force and work as a forensic analyst for various network security operations. The author goes through various scenarios demonstrating different techniques for Intrusion detection using Open Source tools. He introduces Squil, a very robust front-end for Snort that is designed with the Security Analyst in mind. The author brings forth some very interesting points of view based on experience in network security. While the book is rather large, somewhere over 700 pages including the appendices, I found that all the information in the book is worthwhile and relevant.

I am not sure how I was first introduced to the author, Mr. Bejtlich. I cannot remember if I first noticed his work via his excellent blog or this, his first book. Either way, after reading "The Tao of Network Security" by Richard Bejtlich, I feel he has prepared and educated me in a way unlike any other author. The first item you must recognize is the tone that this book dictates right from the outset. The book begins by citing many different authors, their books and their value. I knew immediately that I was in for a treat. And I was right!

I will not attempt to offer a full review as I feel one can gather from other reviews the value of this book. The book is basically broken up into 5 sections. The first 100 pages is an intro to Network Security Monitoring (NSM). The second part is dedicated to the different ways to monitor - I particularly like (and agree) with how the author broke up the different ways of cataloguing NSM - full content, session, and alert. The third section describers NSM processes and the fourth section describes NSM people.

The book, overall, is a superb resource. Not a page goes by without some screenshots of TCPDump, UNIX configs or diagrams. I have heard others' mention they have been given this book to read in their classroom study and I can see why.

I give this book 5 pings out of 5:
!!!!!

If you want to take your network security monitoring to the next level, check out The Tao Of Network Security Monitoring by Richard Bejtlich. It does a good job covering new ground.

Chapter list: The Security Process; What Is Network Security Monitoring?; Deployment Considerations; The Reference Intrusion Model; Full Content Data; Additional Data Analysis; Session Data; Statistical Data; Alert Data: Bro and Prelude; Alert Data: NSM Using Sguil; Best Practices; Case Studies For Managers; Analyst Training Program; Discovering DSN; Harnessing The Power Of Session Data; Packet Monkey Heaven; Tools For Attacking Network Security Monitoring; Tactics For Attacking Network Security Monitoring; The Future Of Network Security Monitoring; Protocol Header Reference; Intellectual History Of Network Security Monitoring; Protocol Anomaly Detection; Index

A sign of a good book is when the author sets out their scope and target audience, and then doesn't stray from it. Bejtlich doesn't try to teach the reader every last thing about every package he can include. Rather, he defines the scope as open source monitoring tools that haven't been written about ad nauseam. Furthermore, there's no wasted space covering installation instructions. He figures you can read the documentation for that. So what you get is meaty information on how to conduct network security monitoring (NSM) using the different packages that are available.

Another nice portion of the book includes the case studies and the analyst training. This not only entertaining reading, but it also bridges the gap between just knowing about the subject to being able to practice those skills as part of your occupation. Very nice feature...

An excellent addition to your network security bookshelf...

Every once in a while you come across a book that really opens your eyes. One that talks in-depth about something completely different. Unfortunately, most technical IT books are rehashes of a bunch of papers and tutorials off the net, and you often wonder whether the time you spent reading the book would have been better spent on google.

The Tao of Network Security Monitoring is not one of these books. It is with great pleasure that I am reviewing what I consider one of the most informative and well written books I have ever come across.

Network Security Monitoring (NSM) is half a science, and half a black art. It requires an in-depth knowledge of packets, protocols, applications, vulnerabilities and black hat tactics. This book focuses on the philosophy behind NSM, the skills required, the tools you need, and the way to set up an effective NSM operation.

The author, Richard Bejtlich, is a former Air Force intelligence officer, and the approach he dictates is almost military in nature. This book covers an introduction to security, what NSM is, how to deploy it, the best tools for the job and the types of things you will see.

I was most impressed by the analysis of normal versus suspicious versus malicious traffic. Since deep packet inspection is one of my hobbies, I am no stranger to reading data off the wire, but I was amazed by the amount of information this man was able to glean by looking at a simple DNS packet !

He explains the differences between full content data (logging everything to the application layer), session data (looking at just the different conversations between hosts), and statistical data. Everything in this book is practical, you can even go to the website and download the same packet traces he uses for explanation and run through them yourself.

This book taught me about a host of new tools, from Argus, to the incredible SGUIL. It taught me a lot of tricks about designing a top notch NSM collection and analysis setup, and more than anything, it introduced me to a completely new mind-set.

In short, this is at present the most enlightening book on my IT bookshelf. I strongly recommend it to anyone who is involved with networks or security. It will be of special interest to the sort of people who get a rush ripping up packets and understanding what happens below the surface. It also goes really well with firewall.cx, since most of the protocols talked about are explained here in detail.

If there is one disappointment, it's the absence of an included CD-ROM containing tools, or perhaps a live FreeBSD CD (Freebie) like the one he introduces in the book.

This one gets a scorching 5/5. Get it now, and open your mind !

This book has everyting as it pertains to network security monitoring. If you read this book from cover-to-cover, then you can consider yourself prepared to deal with anything that comes at you. This book presents material that would normally take years to learn in an easy-to-follow format. This book is a must have for anyone who is serious about their job and wants to make the jump to becoming an expert.