Detection is a Philosophy, Approach, and Methodology...
When building, improving, or operating a security program, aiming for the right balance between prevention and detection/response seems like an obvious choice. I've discussed the question of why this is the case in a number of different pieces I've written for SecurityWeek and others. One might be inclined to conclude that my position on this topic stems from my background in security operations and incident response, where I practiced this methodology for many years. That may certainly be the case, but I do think it is worth examining this concept a bit further in this piece.
In my current position, I spend a lot of time educating people on the merits of security operations and incident response, including a balanced approach consisting of both prevention and detection/response.
What I find fascinating is that I am not alone in my thinking – not by a long shot. Sure, my professional contacts agree with and follow this philosophy, but that is to be expected and doesn't prove much of anything. What I find truly remarkable are my interactions and conversations with non-security or non-technical audiences. I often explain to these audiences that security can and should be approached as a business function aimed at mitigating risk, rather than as an enigma. I discuss some of the risks and threats that the modern organization faces, and I speak to some of the ways in which this risk can be mitigated.
Data Breach Detection
Perhaps not surprisingly to those who read my pieces, during these sessions, I map out a strategic approach to risk mitigation including a formalized incident response process/incident handling life cycle. What may surprise the reader, though, is the speed at which these audiences can understand and grasp the concept of security in this context, at least at a high level. I always enjoy watching the audience transformation, which involves a journey from whatever pre-conceived notion of security each individual may have possessed, to a different understanding of security entirely. These audiences, the overwhelming majority of which have no operational security experience, can quickly understand the merits of a balance between prevention and detection/response. After all, most business leaders understand the concepts of both risk and risk mitigation. Security is merely another domain to which those analytical skills need to be applied.
At the same time, I hear a lot of noise from many in what I would call the "pro-prevention" camp. I hear things like "detection is ineffective" or "detection is dead" or "detection is not a winning strategy". Essentially, the narrative coming out of this camp states that an organization should focus on prevention entirely without paying much mind to detection/response. I'd like to put aside, for the moment, the fact that we have tried this approach for the last 20 years with less than spectacular results, as well as the fact that the approach simply doesn't reflect reality, at least as I have experienced it operationally. I simply can't understand how one could recommend against a balanced approach of both prevention and detection/response.
The people beating the prevention drum aren't fools, which leads me to two potential explanations for this behavior. They either don't really believe what they are saying (i.e., they have some ulterior motive driving their messaging), or they simply don't understand what I, and others are referring to when we discuss detection. In case there is some confusion around what detection is all about, I'd like to make an effort to clear that up.
Let's start at the beginning. Detection is not about anti-virus (AV), Intrusion Detection Systems (IDS), Security Information and Event Management (SIEM), or any other type of technology. Detection is also not about signatures, alerts, events, tickets, or any other type of meta-data. Do security technologies and meta-data play a role in detection? Absolutely. They are necessary for detection, but they are not sufficient.
Detection is a philosophy, approach, and methodology that seeks to identify suspicious or malicious behaviors matching risks and threats the organization is concerned about. The output and success of the detection process is highly dependent on the input to that process. In other words, garbage in leads to garbage out. If one wants to understand why detection rates are so poor across most organizations, one need only look at the content development process used to feed the detection process. The solution to the detection challenge many organizations face isn't to throw away the concept of detection entirely, but rather to improve the content development process feeding it.
A high quality content development process is critical to the success of detection efforts because it is the process that feeds detection. The better the content with which we feed our detection process, the better our detection works for us. I discussed the importance of this topic in additional depth in a previous SecurityWeek piece entitled "Spear Alerting: Improving Efficiency of Security Operations and Incident Response", but would like to highlight some of the steps involved in the development of high fidelity, reliable content:
• Collect the smallest amount of data of highest value and relevance to security operations and incident response that provides the required visibility.
• Identify goals and priorities for detection and alerting in line with business needs, security needs, management/executive priorities, risk/exposure, and the threat landscape. Use cases can be particularly helpful here.
• Craft human language logic designed to extract only the events relevant to the goals and priorities identified in the previous step.
• Convert the human language logic into precise, incisive, targeted queries designed to surgically extract reliable, high fidelity, actionable alerts with few to no false positives.
• Continually iterate through this process, identifying new goals and priorities, developing new content, and adjusting existing content based on feedback obtained through the incident response process. Neither content development nor detection is ever really complete.
Detection/response serves to augment prevention and round out an organization's approach to risk mitigation. Put another way, attackers regularly get by any and all preventative measures. When this occurs, an organization can use detection/response to quickly identify that this has occurred and contain and remediate the activity before it causes damage to the organization. This balanced approach allows the organization to spread its risk mitigation strategy across more than one mitigating factor.
When I listen to the talking points of the pro-prevention camp, perhaps ironically, I hear an ever-greater need for detection/response. Clearly, this is not their intended result. But I do believe that a better understanding of what detection actually refers to benefits everyone and the security community as a whole. The time has come to move the discussion beyond the hype.