Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Analytics

2/29/2016
10:30 AM
Jeff Schilling
Jeff Schilling
Commentary
Connect Directly
Facebook
Twitter
LinkedIn
RSS
E-Mail vvv
50%
50%

Measuring Security: My ‘Dwell Time’ Obsession

How I discovered the critical metric to fuel my drive to create the most secure environment possible.

Throughout my military career, I had two- and three-star generals ask — no, demand — that our security and operations center have measurable cybersecurity metrics. They’d challenge me with the same gamut of questions: “How do you know we are making a difference? Are we getting any better? How do we calculate our return on investment if we don’t know what to measure?” 

I retired from the U.S. Army in 2012. I was never able to answer any of those demands for “good” cybersecurity metrics.

One of the metrics I talked myself out of providing was our number of infected hosts. Is a low number good or bad? If it is low, I am paranoid that I am missing threat activity. If the number is high, there’s a bigger problem at hand. No matter the number, you can never find the denominator (i.e., the actual number of infected hosts). 

From there, I considered another metric: number of security events. This caused me concern as well. Most complex environments detect billions of daily security events. It is impossible to characterize them as true positives or false positives. Plus, I can’t be sure of the number of dreaded true negatives. How many events evaded detection by our security sensors?

Nothing felt informative or effective.

After I left the military, I finally figured it out. I was fortunate enough to manage an incident response and forensics team. Everything a forensics teams does in their investigations is in the context of the Kill Chain. This is the seven-step sequence of events that must occur for a threat actor to achieve their objectives (e.g., steal or destroy data). 

While examining the Kill Chain, the idea dawned on me. I could measure the one variable that a threat actor had to have in order to be successful: dwell time in the network. I needed to eliminate or reduce the amount of time they have to complete the Kill Chain. That’s it. If I could limit dwell time, the threat actor would not have what they needed to progress through the Kill Chain.

Dwell time, which is the duration a threat actor has in an environment before they are detected or eliminated by the security team, is something I could measure fairly accurately with a good forensics investigation.

There are a number of well-known dwell time benchmarks to get a good baseline to measure against. Most of the major annual cybersecurity reports now cite the average dwell time number as being over 200 days. We can do better. We must do better.

With this renewed focus, I centered my security strategy around reducing dwell time by: 

  • Leveraging hardened CIS server builds
  • Building an aggressive patching program focused on the most likely targeted servers in our data centers
  • Using on-access scans for anti-malware tools
  • Integrating traffic-shaping at that edge, with IP reputation management, to remove the noise for network intrusion detection and Layer 7 inspection
  • Deploying a ‘zero-trust’ model in provision servers (i.e., only ports and protocols required for operation are open)
  • Leveraging a SIEM with great correlation 

Dwell time is my obsession. Through diligence and careful process, we continue to see this number drop in our customer environments. This change in thinking rallies the team around one standard (measuring the amount of time from detection to eradication) that is quantifiable and can be leveraged to calculate the effectiveness of a security strategy and overall posture.

No metric is perfect. But any other approach has too many unknowns that will overrun you with false positives. Until a new standard is found, dwell time will continue to be my obsession.

Related Content:

 

Interop 2016 Las Vegas

Find out more about security threats at Interop 2016, May 2-6, at the Mandalay Bay Convention Center, Las Vegas. Register today and receive an early bird discount of $200.

Jeff Schilling, a retired U.S. Army colonel, is Armor's chief security officer. He is responsible for the cyber and physical security programs for the corporate environment and customer-focused capabilities. His areas of responsibilities include security operation, governance ... View Full Bio
Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
RyanSepe
50%
50%
RyanSepe,
User Rank: Ninja
2/29/2016 | 12:41:25 PM
False Negatives
"Plus, I can't be sure of the number of dreaded true negatives. How many events evaded detection by our security sensors?"

You may want to update with false negatives.
Mobile Banking Malware Up 50% in First Half of 2019
Kelly Sheridan, Staff Editor, Dark Reading,  1/17/2020
Exploits Released for As-Yet Unpatched Critical Citrix Flaw
Jai Vijayan, Contributing Writer,  1/13/2020
Microsoft to Officially End Support for Windows 7, Server 2008
Kelly Sheridan, Staff Editor, Dark Reading,  1/13/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Write a Caption, Win a Starbucks Card! Click Here
Latest Comment: This comment is waiting for review by our moderators.
Current Issue
The Year in Security: 2019
This Tech Digest provides a wrap up and overview of the year's top cybersecurity news stories. It was a year of new twists on old threats, with fears of another WannaCry-type worm and of a possible botnet army of Wi-Fi routers. But 2019 also underscored the risk of firmware and trusted security tools harboring dangerous holes that cybercriminals and nation-state hackers could readily abuse. Read more.
Flash Poll
[Just Released] How Enterprises are Attacking the Cybersecurity Problem
[Just Released] How Enterprises are Attacking the Cybersecurity Problem
Organizations have invested in a sweeping array of security technologies to address challenges associated with the growing number of cybersecurity attacks. However, the complexity involved in managing these technologies is emerging as a major problem. Read this report to find out what your peers biggest security challenges are and the technologies they are using to address them.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-7227
PUBLISHED: 2020-01-18
Westermo MRD-315 1.7.3 and 1.7.4 devices have an information disclosure vulnerability that allows an authenticated remote attacker to retrieve the source code of different functions of the web application via requests that lack certain mandatory parameters. This affects ifaces-diag.asp, system.asp, ...
CVE-2019-15625
PUBLISHED: 2020-01-18
A memory usage vulnerability exists in Trend Micro Password Manager 3.8 that could allow an attacker with access and permissions to the victim's memory processes to extract sensitive information.
CVE-2019-19696
PUBLISHED: 2020-01-18
A RootCA vulnerability found in Trend Micro Password Manager for Windows and macOS exists where the localhost.key of RootCA.crt might be improperly accessed by an unauthorized party and could be used to create malicious self-signed SSL certificates, allowing an attacker to misdirect a user to phishi...
CVE-2019-19697
PUBLISHED: 2020-01-18
An arbitrary code execution vulnerability exists in the Trend Micro Security 2019 (v15) consumer family of products which could allow an attacker to gain elevated privileges and tamper with protected services by disabling or otherwise preventing them to start. An attacker must already have administr...
CVE-2019-20357
PUBLISHED: 2020-01-18
A Persistent Arbitrary Code Execution vulnerability exists in the Trend Micro Security 2020 (v160 and 2019 (v15) consumer familiy of products which could potentially allow an attacker the ability to create a malicious program to escalate privileges and attain persistence on a vulnerable system.