Information Systems Security Engineer (ISSE)
Fort Belvoir, VA
Full Time
Defense
Mid Level
Tetrad Digital Integrity (TDI) is a cybersecurity firm built for high-consequence environments where mission, complexity, and trust intersect. Our single focus has been delivering cyber solutions to effectively manage risk & the business of cyber for 25 years!
We are seeking an ISSE with an active Secret Clearance to provide onsite customer support at the Fort Belvoir customer site, 5 days a week.
RESPONSIBILITIES:
We are seeking an ISSE with an active Secret Clearance to provide onsite customer support at the Fort Belvoir customer site, 5 days a week.
RESPONSIBILITIES:
- Must possess excellent written and oral communication skills, with an ability to brief Program Management, Government customers (to include System Owner and/or COR) and Government Cybersecurity personnel. Briefings might be daily, weekly, monthly or on an ad-hoc basis. Must be detail oriented.
- Strong understanding of the DoD Risk Management Framework (RMF) and experience with tools such as Enterprise Mission Assurance Support Service (eMASS), ESS/HBSS, ACAS, patching solutions, etc.
- Create and manage authorization packages in eMASS for two enclaves. Collaborate with cybersecurity teams to support Authorization to Operate (ATO) packages, Plans of Action & Milestones (POA&Ms), and audit readiness, while maintaining detailed system documentation.
- Document and manage vulnerabilities in a Plan of Actions and Milestones (POA&M) and provide updates on open vulnerabilities to Program Management and Government personnel.
- Implement and maintain security controls in compliance with DISA Security Technical Implementation Guides (STIGs) and DoD cybersecurity policies to ensure the secure configuration of all systems.
- Perform system hardening, patching, and vulnerability remediation using tools such as the Assured Compliance Assessment Solution (ACAS) and Endpoint Security Solutions (ESS).
- Apply and manage patches and updates across all Linux and Windows systems in accordance with DoD patch management policies, ensuring timely remediation of vulnerabilities.
- Expertise in Windows Server and/or Linux (RHEL) administration, virtualization technologies (VMware, Hyper-V, Nutanix), and a comprehensive understanding of networking fundamentals, including routing, DNS, and firewalls.
- Hands-on experience with DoD-specific security tools such as ACAS, ESS (formerly HBSS), and Security Content Automation Protocol (SCAP) or other STIG tools.
QUALIFICATIONS:
- Bachelor of Science degree in a related area
- 10-15 overall years of experience. Can have less overall YOE with a degree with 5 – 10 years of DoD/DoW experience in systems support and cybersecurity
- DoD 8570 IAT Level II certification (such as Security+ CE, CYSA+, or CASP+ CE) is required
TDI does business with the federal government, which restricts employment to individuals who are either US citizens or lawful permanent residents of the United States.
“TDI is an Equal Opportunity Employer. Employment decisions are made based on individual qualifications, merit, and business needs. We do not discriminate in employment opportunities or practices based on race, color, religion, sex, or national origin, in accordance with applicable federal laws.”

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