Jeff McJunkin

Jeff's path into offensive security began in systems and network administration. Early roles in enterprise IT, systems engineering, and infrastructure management gave him firsthand experience building and maintaining the environments he would later be tasked with assessing. After moving into professional penetration testing, he developed deep expertise in Active Directory security, enterprise attack paths, post-exploitation operations, and realistic adversary emulation. His current role in Cyber Applied Research at OpenAI adds another chapter to a career spanning enterprise infrastructure, offensive security consulting, and technical instruction.

Jeff holds many industry certifications, including the GIAC Security Expert (GSE #128), GIAC Exploit Researcher and Advanced Penetration Tester (GXPN), and GIAC Penetration Tester (GPEN) certifications. Beyond consulting and instruction, he has architected multiple generations of the SANS Core NetWars cyber ranges, contributed to the SANS Holiday Hack Challenge, and helped develop offensive security training used by thousands of practitioners worldwide. His work reflects a long-standing commitment to hands-on learning, realistic adversary simulation, and practical skill development for security teams. Jeff is also a faculty member of the SANS Technology Institute, which has been designated an NSA Center of Academic Excellence in Cyber Defense and is a multi-year winner of the National Cyber League competition.

Students consistently describe Jeff as an instructor who makes complex technical concepts approachable through practical demonstrations, realistic stories, and extensive hands-on exercises. His teaching philosophy centers on helping practitioners understand not only how attacks work, but why they succeed and how organizations can meaningfully reduce risk. Outside the classroom, Jeff likes to experiment with various side quests using AI systems, such as automated reverse-engineering, exploit generation, and augmenting his own knowledge. He also enjoys hiking, spending time with his lovely wife and two children, and disconnecting from the outside world to decompress and enjoy vacation time.

Qualifications Summary

• Member of Technical Staff, Cyber Applied Research, OpenAI
• SANS Principal Instructor; Co-author of SEC560: Enterprise Penetration Testing and author of SEC580: Metasploit for Enterprise Penetration Testing
• Founder and Principal Consultant, Rogue Valley Information Security
• Led penetration testing and red team engagements for Fortune 100 organizations
• Architected multiple generations of SANS Core NetWars Cyber Ranges

Certifications

• GSE - GIAC Security Expert Certification (#128)
• CCNA - Cisco Certified Network Associate
• CISSP - Certified Information Systems Security Professional
• GXPN - GIAC Exploit Researcher and Advanced Penetration Tester
• GPEN - GIAC Penetration Tester Certification
• GCIH - GIAC Certified Incident Handler
• GREM - GIAC Reverse Engineering Malware Certification
• GCFA - GIAC Certified Forensic Analyst
• GCIA - GIAC Certified Intrusion Analyst
• GCED - GIAC Certified Enterprise Defender
• GMOB - GIAC Mobile Device Security Analyst
• GPYC - GIAC Python Coder
• GCFE - GIAC Certified Forensic Examiner
• GSEC - GIAC Security Essentials