About Us

About Active Countermeasures

Active Countermeasures is a group of like-minded geeks that believe in giving back to the security community. We do this through free training, thought leadership, and both open source and affordable commercial tools.

As a community, we have tools and techniques to help protect our networks (firewalls, AV, log review, etc.). We also have tools and processes to recover when a system is compromised (incident handling and forensics). What’s been missing is the bridge between the two; the ability to quickly identify that our protections have failed and recovery needs to be implemented. There are very few tools in this space and no open standards or attestation requirements.

How do you validate that your network is free of intruders? This is the problem Active Countermeasures is focused on solving.


John Strand

John is a published author, Senior SANS Instructor, the owner of Black Hills Information Security, and arguably the most recognized name in the threat hunting industry. He has also created some of the best open source threat hunting tools that are available. As a frequent webcast and Black Hat presenter, John has always been passionate about sharing his security skill set with the masses. He currently teaches multiple ``Pay What You Can`` training courses with Antisyphon Training. His focus has been on empowering others to take the steps needed to secure their network.

Chris Brenton

Chris has been a leader in the IT and security industry for over 25 years. He’s a published author of multiple security books and the primary author of the Cloud Security Alliance’s online training material. As a Fellow Instructor, Chris developed and delivered multiple courses for the SANS Institute and now teaches multiple training courses for Antisyphon Training. As an alumni of Y-Combinator, Chris has assisted multiple startups, helping them to improve their product security through continuous development and identifying their product market fit.

Development Team

Operations | Programming | Design | Product Testing & QA | Customer Support
Yelizaveta Tsibur

Liza has a bachelors in Computer Science from the South Dakota School of Mines and Technology. She has been working for Active Countermeasures since 2015. In her free time she enjoys snowboarding, rock climbing, tabletop RPGs, and video games.

Logan Lembke

Logan is a graduate student of Computational Sciences and Robotics at the South Dakota School of Mines and Technology. His research is in the fields of computer vision and machine learning. He has been a part of the ACM team since 2016. Off the job, he spends his time hiking, gardening, reading, and playing video and tabletop games.

Naomi Kramer

Naomi has a bachelor’s degree in Computer Science from Dakota State University. She specializes in modern full-stack development and likes to dabble in iOS development. Her interests include oil painting, Swedish ciders, paddleboarding, retro hardware game modding with her husband, and adventuring with her two Siberian Huskies.

Bill Stearns

Bill provides Customer Support, Development, and Training for Active Countermeasures. He has authored numerous articles and tools for client use. Bill was the chief architect of one commercial and two open-source firewalls and is an active contributor to multiple projects in the Linux development effort. His spare time is spent coordinating and feeding a major anti-spam blacklist. Bill's articles and tools can be found in online journals at http://github.com/activecm/ and http://www.stearns.org.

Keith Chew

Keith joined the ACM team in 2018 and describes his career at Active Countermeasures as his dream job. His fascination with computing and processes stems from working with his first personal computer in 1982 - a TI-99/4A. Keith sees himself as fortunate for the opportunity to apply his passion towards a career that assists in the advance of technology. Beyond computing and electronics, Keith also enjoys anything with an engine, wheels, or wings.

Brian Fehrman

Brian has worked as a security analyst/researcher for BHIS since 2014. He joined the Active Countermeasures team as a developer in 2020. He is currently pursuing a Ph.D. in Cyber Operations from Dakota State University. Outside of computers, Brian enjoys wake surfing, home-improvement, mechanics, and is an avid Brazilian Jiu-Jitsu enthusiast.

David Quartarolo

David has a bachelors in Computer and Network Security from Wilmington University. He has a background in networking and infrastructure security. David joined the ACM team in the Fall of 2021. In his free time, David enjoys spending time with his family and runs his son's Cub Scout Pack. David is also a proud U.S. Navy Submarine Veteran.

Kelly Dance

Kelly joined Active Countermeasures in the summer of 2022. He previously interned at our sister company BHIS for two years. Kelly is currently a student at Colorado School of Mines double majoring in Computer Science and Applied Math. In his free time, Kelly does competitive programming and recently participated in the ICPC North American Championship.

Ethan Robish

Ethan has worked with Active Countermeasures since the beginning. Previously, he implemented defensive security solutions for the Exchange Online security team as a Microsoft intern. Ethan also competed on a programming team that placed 3rd in the International Collegiate Programming Competition Regionals, allowing them to compete in the ICPC World Finals.

Samuel Carroll

Samuel attended South Dakota School of Mines and Technology from 2011 until 2018 earning both a bachelor's and a master's degree in Computer Science. He started working at Active Countermeasures in the summer of 2017 as an intern and upon graduating he started working full-time. In addition to programming he enjoys wood-working, bicycling, reading, climbing and ignoring the Oxford Comma.

Growth Team

Project Management | Business Development | Content Marketing | Data Analytics | Growth Hackers
Jason Blanchard

Jason has been happily adopted into the hacker community even though he ``works in marketing.`` He’s had every dream job imaginable: teaching film making, owning the world’s most famous comic book store, and fostering the infosec community efforts for SANS. Now he humbly brings his particular set of skills to Active Countermeasures.

Kris Chew (K.C.)

Kris (K.C.) joined Active Countermeasures in April 2018. With her strong background in logistics, she has become the Inside Sales Manager. Her attention to detail and organization also landed her in a position to manage and organize events for the company. In her free time, K.C. is passionate about shark conservation and loves to spend time with her husband and their cats.

Shelby Perry

Shelby has a strong background in Social Media Marketing and Event Management. Her interpersonal skills and passion for community building are what lead her to her position as Content & Community Manager at Active Countermeasures. When she’s not working, Shelby enjoys spending time with her family.

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