Brennon works as a Vulnerability Analyst and Penetration Tester for Rackspace identifying and reducing risks and threats to Rackspace's computer networks. Prior to Rackspace, Brennon worked for the Air Force, in both active duty and civilian roles, and for the private sector.

He is the author of the "The Cyber Plumber's Handbook", the definitive guide to SSH tunneling, which is free for students. He dabbles in bug bounties as part of the Synack Red Team and is developing a phishing prevention platform called PhishBarrel.