Security System Administrator

Antenna Research Associates, Inc.

$80K — $110K *
Information Technology
Less than 5 years of experience
Job Overview by Ladders

Qualifications

  • 3+ years of experience as a System Administrator in a cybersecurity-focused environment
  • Hands-on experience supporting classified systems (CUI, Secret, or higher)
  • Strong knowledge of Windows Server and/or Linux administration
  • Experience with RMF, NIST 800-53 controls, and ATO processes
  • Bachelor's degree in Computer Science, Information Technology, Cybersecurity, or related field; advanced degree preferred
  • Industry certifications such as Security+, CompTIA CASP+, and Microsoft/Linux certifications preferred

Responsibilities

  • Administer and secure classified information systems according to DoD policies
  • Perform system maintenance including patching and vulnerability remediation
  • Design, deploy, and manage Windows/Linux domains and Active Directory
  • Support system accreditation under RMF and implement security controls
  • Monitor performance and respond to security incidents
  • Maintain secure configurations for all IT devices
  • Collaborate with teams to ensure compliance and operational readiness

Benefits

  • Opportunity to work in a highly technical and classified environment
  • Collaboration with cross-functional teams including engineering and security
  • Professional development opportunities in cybersecurity
  • Potential for travel to various company locations as needed
  • Contributions to significant national defense projects
Full Job Description
Job Summary

We are seeking an experienced Security System Administrator to support and maintain systems within the enterprise cybersecurity and compliance-driven environment. This role requires a technically proficient professional capable of operating within classified environments, ensuring system integrity, security, and compliance with federal DoD (DoW) standards.

Essential Functions

Reasonable accommodation may be made to enable individuals with disabilities to perform the essential functions.

  • 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
  • Support system accreditation efforts under RMF, including implementation of NIST 800-53 security controls
  • 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
  • Maintain documentation including system configurations, SOPs, and change management records
  • Support audits, inspections, and security assessments (e.g., DCSA reviews)
  • Participate in system buildouts, upgrades, and infrastructure improvements
  • Assist with COMSEC as an ALT COMSEC Manager


Position Qualifications

In compliance with federal law, all persons hired will be required to verify identity and eligibility to work in the United States and to complete the required employment eligibility verification form upon hire.

Competency Statements
  • Adaptability - Adapts to change, open to new ideas and responsibilities
  • Communication - Ability to communicate thoughts clearly, both oral and written in an honest, open and timely manner
  • Job Knowledge - Understands facets of job, aware of duties and responsibilities, keeps job knowledge current
  • Technical Skill - Possesses the knowledge and skills needed to perform a job or role effectively
  • Dependability - Meets deadlines, works independently or in a team environment, is accountable, maintains focus, good attendance record
  • Quality - Strives to eliminate errors, accurate work is a priority, seeks opportunities to improve products
  • Ethics - Honest, accountable, maintains confidentiality
  • Initiative / Take Ownership - Takes action, seeks new opportunities, strives to see projects to completion, meaning own your job and see it through
  • Decision Making - Problem solve and critical thinking skills, be able to reach a decision, takes thoughtful approach when considering options, seeks input from others, makes difficult decisions
  • Customer Focus - Understands and can meet the needs in a customer-centric (Internal and External) environment and build strong relationships. Promotes a positive image of the company and strives to solve issues raised by customers

Experience and Skills

  • 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
  • Proven ability to work both independently and within cross-functional teams
  • Strong troubleshooting, analytical, and problem-solving skills
  • 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


Education

Required

  • 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)


Preferred

  • Relevant industry certifications such as:
  • Security+ (DoD 8570/8140 compliant)
  • CompTIA CASP+, CompTIA A+, CompTIA Network+
  • Microsoft, Linux, or VMware certifications (e.g., MCSA/MCSE, RHCSA/RHCE, VCP)

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