Founder of Pwnie Express, OSCP instructor, and hands-on penetration tester since 2011. David runs the Marin Cyber consulting practice from Marin County, California.
David’s career started in systems administration and security engineering, moving fully into offensive security in 2011 when he founded Pwnie Express. There he created the Pwn Plug, a penetration testing device for remote assessment of wired, wireless, Bluetooth, and cellular networks, followed by the Pwn Phone and the Pwn Pulse platform. Pwnie’s products earned SC Magazine’s Innovator of the Year and PC Magazine’s Editors’ Choice, and appeared in Wired, Ars Technica, Forbes, NPR, and Mr. Robot. Over the years Pwnie Express grew from a basement in Vermont to a venture-backed success acquired by Outpost24 in 2019.
During his time at Pwnie Express, David obtained a DARPA grant to build covert pentesting hardware (Power Pwn), acquired a U.S. patent for remote security assessment (Pwn Plug), built the tech behind NPR’s Project Eavesdrop, and presented at Defcon and other venues on ethical hacking and privacy.
After Pwnie Express, David obtained his OSCP, started an independent consulting practice, served as an Adjunct Professor for Norwich University’s Cybersecurity bachelor’s program, and delivered ethical hacking workshops at UC Berkeley, San Francisco City College, and Bay Area youth programs.
In 2020, shortly after relocating to San Francisco, David assumed the role of Principal Security Engineer at Udemy, leading the vulnerability management, threat monitoring, and penetration testing programs through multiple acquisitions, international expansion, and company IPO.
In 2025, David relocated to Marin County and returned to independent work, creating Marin Cyber, a consulting practice delivering expert penetration testing services to Bay Area and national customers across a variety of industries and compliance frameworks (PCI, HIPAA, HITRUST, FedRAMP, NIST, ISO).
