Security System Administrator

About the role

Support and maintain systems within the enterprise cybersecurity and compliance-driven environment. Operate within classified environments, ensuring system integrity, security, and compliance with federal DoD (DoW) standards.

Responsibilities

• Administer, maintain, and secure classified information systems in accordance with DoD and organizational policies
• Perform routine system maintenance, including patching, updates, and vulnerability remediation (e.g., STIG compliance, SCAP scans)
• Design, deploy, and manage Windows/Linux domains, including Active Directory configuration, Group Policy management, and system hardening
• Maintain documentation including system configurations, SOPs, and change management records
• Monitor system performance, logs, and security events; respond to incidents as required
• Implement and maintain secure configurations for servers, workstations, and network devices
• Collaborate with ISSM/ISSO, network teams, and engineering staff to ensure continuous compliance and operational readiness
• Support audits, inspections, and security assessments (e.g., DCSA reviews)
• Assist with COMSEC as an ALT COMSEC Manager

Qualifications

• 3+ years of experience as a System Administrator in a cybersecurity-focused or compliance-driven environment
• Hands-on experience supporting classified systems (CUI, Secret, or higher)
• Strong knowledge of: Windows Server and/or Linux administration, Active Directory, DNS, DHCP, and Group Policy, system hardening (STIGs), patch management, and vulnerability remediation
• Experience with RMF, NIST 800-53 controls, and ATO processes
• Ability to operate as a Subject Matter Expert (SME) across multiple technical domains
• Prioritize troubleshooting, analytical, and problem-solving skills
• Proven ability to work both independently and within cross-functional teams
• Conduct site visits and attend meetings at various company locations. Travel up to 10% of the time as required
• Experience with Special Access Programs (SAP) and SIPRNet

Skills

• Bachelor’s degree in Computer Science, Information Technology, Cybersecurity, or a related technical field; advanced degree preferred
• Equivalent combination of education and relevant hands-on experience (e.g., 3+ years of system administration in secure/classified environments)
• Relevant industry certifications such as: Security+, CompTIA CASP+, CompTIA A+, CompTIA Network+, Microsoft, Linux, or VMware certifications (e.g., MCSA/MCSE, RHCSA/RHCE, VCP)

Benefits

Antenna Research Associates, Inc. is an equal opportunity employer committed to a policy of non-discrimination and affirmative action. We do not discriminate based on race, color, religion, sex, national origin, disability, protected veteran status, or any other legally protected status.