Jeffrey Shearer

During three decades as an industrial and distributed control system designer, architect, and implementer, Jeffrey Shearer has come to see that wisdom in the field can only come from understanding the foundational elements of knowledge and having the practical experience to implement them effectively. So his teaching philosophy as a Certified Instructor of SANS ICS612: ICS Cybersecurity In-Depth is to provide students with the pertinent knowledge and hands-on environment they need to take on the pressures they’ll face in the real world.

More About Jeffrey


Jeff brings a unique background to the classroom, having spent much of his career with Rockwell Automation and with a wide range of original equipment manufacturers working across industrial sectors, from automotive to food and beverage, mining, oil and gas, water and wastewater, pulp and paper, chemicals, pharmaceuticals, plastics, and machinery. While most ICS professionals have a computer science background, Jeff has an understanding of mechanical, hydraulic, and pneumatic systems, and the ability to control them with automation, that sets him apart. He has worked in almost every phase of the automation lifecycle, but has also been employed as an embedded firmware engineer and a software product designer. Today he is the owner of Gray Man Cyber and works with clients from many different sectors.

“As a currently practicing ICS cybersecurity professional with experience in so many different industrial sectors, I have wide exposure to these markets that I can share with my students,” Jeff explains. “I've either solely designed or shared in the automation designs of thousands of systems – no kidding! – and I try to bring the benefits of that real-world experiences into the classroom.”

Jeff is passionate about providing future ICS cybersecurity professionals with targeted basic building blocks that they will be able to draw on to address each unique situation they’ll face going forward.

“Most of our students come to us with very little hands-on experience with ICS system components. As one student told me, ‘every ICS cybersecurity class I've had shies away from the PLC, HMI, and other ICS devices.’ To overcome this, the course first must present the salient points of what needs to be learned and provide access to the relevant ICS devices. To secure something, be it a computer or an ICS system, you need to know what it is and how it works. In ICS612, we bridge the ICS knowledge gap by providing the learning material in a digestible format and the equipment to gain the experience. This leads to effective learning with students being able to solve more complex problems as the course progresses.”

Raised in a small town in the Midwest where most people worked in local factories, Jeff started tinkering with mechanical and electrical systems at an early age with the goal of working in maintenance instead of on the factory line.

“That was my introduction to automation. I was 19 when I programmed my first PLC and I loved it!” he recalls. “I still find factories and plants to be modern-day works of art. How a product is produced still fascinates me to this day.”

In terms of career highlights, Jeff points to his research that eventually led to an advanced control algorithm to control hydraulic pressure and velocity profiles with a PLC.

“I had worked on mechanical and hydraulic systems long enough to know that sometimes the embedded system (PLC) could cause instability in movement and pressure instead of correcting the behavior through traditional control methods like PID. I thought that the embedded controller or a specialty I/O card could model the machine's performance and be used to stabilize the machine. I also knew it could be used to tell the machine operators when they were trying to achieve a velocity or pressure profile that the machine wasn't capable of performing. I was able to prove this theory and eventually Rockwell Automation provided this functionality in some of their special I/O modules and it turned into my first patent.”

Jeff became inspired to join the SANS ICS staff after having taken courses at SANS.

“It's not easy to become SANS Certified, but it has been worth the journey, and I'm honored to be a SANS instructor and will continue to strive to educate myself so I can pass that knowledge onto my students,” Jeff explains. “I enjoy teaching because the depth of my experience allows me to venture into deep questions and conversations with my students without being uncomfortable. If you are going to teach a subject, you should have experience with much more than what's on the syllabus. In the ICS world, that means gaining experience with mechanical, electrical, and automation systems.”

Outside of work, Jeff has a private pilot license and has even rebuilt a 1972 Piper Cherokee 140 and got it officially re-certified by the FAA. He is also a certified martial arts instructor.



ICS Hot Take videos on SANS ICS YouTube

Ghost in the Network vs. Ghost in the Machine

Infrastructure Cybersecurity Trends and Developments - ARC 2018 Forum

Fake IO - Affecting Level 0-1 Data - ARC 2019 Forum


  • CISSP®
  • PMP


  • Ransoming Critical Infrastructure - Emergency Webcast
  • Ghost in the Network vs. Ghost in the Machine
  • Train Your Hands and Your Mind
  • Getting Your Hands Dirty with Industrial Control Systems




  • Rockwell Automation Engineer of the Year, Application Discipline
  • Multiple Rockwell Automation Innovation Awards
  • Rockwell Automation Business Innovation Award


  • Injection Molding Controller with Machine Modeling
  • Access Control Method for Disconnected Automation Systems


  • Architectural Challenges of Interoperability between Process Analytical Technologies (PAT) and Automation Systems
  • Nonlinear Control and Decision Making Using Fuzzy Logic in ControlLogix
  • Sharing the Wealth: New Small Logic Controllers Give Smaller Molders Many of the Benefits Once Limited to Large-scale Operation
  • Securely Traversing IACS Data across the Industrial Demilitarized Zone
  • Cloud Connectivity to a Converged Plantwide Ethernet Architecture
  • Deploying Identity and Mobility Services within a Converged Plantwide Ethernet Architecture
  • Deploying Industrial Firewalls within a Converged Plantwide Ethernet Architecture
  • Converged Plantwide Ethernet (CPwE) Design and Implementation Guide
  • Control Magazine: “Mechanical Security Needs Diverse Experts;” and “Achieving a Balance between Convenience and Security”