I often find myself in situations trying to explain the value of Network Security Monitoring (NSM). This very short fictional conversation explains what I mean. This exchange
did not happen but I like to contemplate these sorts of dialogues.
NSM Advocate: I recommend deploying network-based sensors to collect data using NSM principles. I will work with our internal business units to select network gateways most likely to yield significant traffic. I will build the sensors using open source software on commodity hardware, recycled from other projects if need be.
Manager: Why do we need this?
NSM Advocate: Do you believe all of your defensive measures are 100% effective?
Manager: No. (This indicates a smart manager. Answering Yes would result in a line of reasoning on why Prevention Eventually Fails.)
NSM Advocate: Do you want to know when your defensive measures fail?
Manager: Yes. (This also indicates a smart manager. Answering No would result in a line of reasoning on why ignorance is not bliss.)
NSM Advocate: NSM will tell us when we fail. NSM sensors are the highest impact, least cost way to obtain network situational awareness. NSM methodologies can guide and validate preventative measures, transform detection into an actionable process, and enable rapid, low-cost response.
Manager: Why can't I buy this?
NSM Advocate: Some mainstream vendors are realizing a market exists for this sort of data, and they are making some impact with new products. If we had the budget I might propose acquiring a commercial solution. For the moment I recommend pursuing the do-it-yourself approach, with transition to a commercial solution if funding and product capabilities materialize.
Manager: Go forth and let your sensors multiply.Now you know that it's fiction.
Notice the crux of the argument is here:
Do you believe all of your defensive measures are 100% effective? As a statement, one would say
Because prevention eventually fails, you should have a means to identify intrusions and expedite remediation. A manager hearing that statement is likely to respond like this.
Manager: Do you mean to tell me that all of the money I've spent on firewalls, intrusion prevention systems, anti-virus, network access control, etc., is wasted?NSM Advocate: That money is not wasted. It's narrowed the problem space, but it hasn't eliminated the problem.This is a tough argument to accept. When I worked at Foundstone the company sold a vulnerability management product. Foundstone would say "buy our product and you will be secure!" I worked for the incident response team. We would say "...and when you still get owned, call us." Which aspect of the business do you think made more money, got more attention, and received more company support? That's an easy question. How is a salesperson supposed to look a prospect in the eye and say "You're going to lose. What are you going to do about it?"
Many businesses are waking up to the fact that they've spent millions of dollars on preventative measures and they still lose. No one likes to be a loser. The fact of the matter is that winning cannot be defined as zero intrusions. Risk mitigation does not mean risk elimination. Winning has to be defined using the words I used to explain risk in my first book:
Security is the process of maintaining an acceptable level of perceived risk.This definition does not eliminate intrusions from the enterprise. It does leave an uncomfortable amount of interpretation for the "acceptable level" aspect. You may have noticed that most of the managers one might consider successful are usually self-described or outwardly praised as being risk-takers. On the other side of the equation we have security professionals, most of whom I would label as risk-avoiders.
The source escapes me now, but a recent security magazine article observed that those closest to the hands-on aspects of security rated their companies as being the least secure. Assessments of company security improved the farther one was removed from day-to-day operations, such that the CIO and above was much more positive about the company's security outlook. The major factor in this equation is probably the separation between the corner office and the cubicle, but another could be the acceptable level of risk for the parties involved. When a CIO or CEO is juggling market risk, credit risk, geo-political risk, legal risk, and other worries, digital risk is just another item in the portfolio.
The difference between digital risk and many of the other risk types is the consequences can be tough to identify. In fact, the more serious the impact, the least likely you could be to discover the intrusion.
How is that possible? What causes more damage: a DDoS attack that everyone notices because "the network is slow," or a stealthy economic competitor whose entire reason in life is to avoid detection while stealing data?
Without evidence to answer the question
are you secure?, managers practice management and defense by belief instead of management and defense by fact.
One of you wrote recently to ask about the status of the open source Network Security Monitoring suite called Sguil. You noticed the last release of Sguil (0.6.1) occurred in February 2006. I can assure you Sguil is not dead. In fact, just last week I wrote an article for a new BSD magazine about installing the sensor and server components of Sguil 0.7.0 (from CVS on FreeBSD 7.0. 
