Principal Systems Administrator (Linux & Windows) with Security Clearance

Principal Systems Administrator (Linux && Windows) Position Overview Type: Full-Time Location: Fort Huachuca, AZ Travel: None expected Clearance: Department of Defense (DoD) Secret security clearance.

Work Authorization: U.S. Citizenship required Summary/Objective Five Stones Research Corporation (5SRC) is seeking energetic candidates to join our established and growing Huntsville-headquartered team. Essential Functions Endpoint Lifecycle Management && MECM/SCCM Administration

• Serve as the primary administrator for Microsoft Endpoint Configuration Manager (MECM / SCCM), managing infrastructure health, site systems, distribution points, and client agent health across all connected enclaves.
• Engineer, test, deploy, and maintain standardized Windows Operating System Deployment (OSD) task sequences and baseline golden images.
• Package, test, distribute, and automate application installations, scripts, and software updates across heterogeneous lab and hosting workstations and servers.
• Manage and orchestrate enterprise-wide software update distribution using Software Update Points (SUP) integrated with Windows Server Update Services (WSUS).
• Create and deploy custom compliance baselines and configuration items (CIs) to enforce security settings, STIG configurations, registry keys, and audit contr ols.
• Develop custom MECM queries, device collections, and reports (SSRS) to provide real-time hardware/software inventory, asset discovery, and compliance auditing. Systems Administration (Linux && Windows)
• Administer, build, configure, and maintain physical and virtual Red Hat Enterprise Linux (RHEL) servers, modern Windows Servers (2019/2022), and Windows 10/11 workstations.
• Manage core directory and identity infrastructure, including Active Directory Domain Services (AD DS), Group Policy Objects (GPOs), DNS, DHCP, and role-based access contr ol.
• Troubleshoot and maintain enterprise Linux services, including SE Linux policies/security contexts, daemon services (systemd, chronyd), file systems (/opt, logical volumes), and local package managers.
• Maintain hypervisor and storage infrastructure, including Nutanix, VMware ESXi/vCenter, and enterprise backup/restore solutions (e.g., Cohesity, snapshots).
• Support basic multi-tier database hosting and connectivity for Oracle and Microsoft SQL server backends.
• Process, approve, and maintain user access documentation and account provisioning via DD Form 2875 and identity management systems.
• Issue, configure, and troubleshoot Public Key Infrastructure (PKI) certificates, CAC authentication, and secure remote protocols across all client and server endpoints. Cybersecurity, Vulnerability Management && Compliance
• Maintain strict system security posture in compliance with Defense Information Systems Agency (DISA) Security Technical Implementation Guides (STIGs) and Security Requirements Guides (SRGs).
• Execute, review, and analyze weekly Assured Compliance Assessment Solution (ACAS / Tenable Nessus) vulnerability scans and monthly STIG evaluations.
• Rapidly remediate identified CVEs, IAVM alerts, CTO/DTO directives, and vendor patches across both Windows and Linux fleets.
• Draft, track, and update Plans of Action and Milestones (POA&&Ms) for items requiring architectural mitigations or extended test schedules.
• Maintain endpoint security agents across all hosts, including Trellix/ePO agents, endpoint detection and response (EDR), and application whitelisting tools (e.g., fapolicyd).
• Monitor and analyze system, security, and application logs using SIEM and centralized log management tools (e.g., LogRhythm, Elastic Fleet).

Required Qualifications

• One of the following combinations of education and experience:
• Requires a Master's degree
• Bachelor's degree with at least 4 years of experience
• Associate's and at least 6 years of experience.
• One year of experience can be substituted by 15 semester hours completed towards a Master's degree. Additional certifications (other than those required for the position) in the area of specialization be substituted for experience but varies by certification. The degree must be in a relevant technical curriculum and experience must be related to the job duties.
• Minimum of 3-5+ years of hands-on systems administration experience across mixed Linux (RHEL) and Windows enterprise server/workstation environments.
• Minimum of 2+ years of dedicated, hands-on administration of Microsoft Endpoint Configuration Manager (MECM / SCCM) in an enterprise or lab environment.
• Active DoD 8570/8140 IAT Level II Baseline Certification (e.g., CompTIA Security+ CE, CCNA Security, CySA+, GICSP, GSEC, or SSCP).
• Relevant computing environment (CE) / vendor training or certification in Microsoft Windows Server/MECM or Red Hat Enterprise Linux (or ability to complete within 6 months of hire).

Preferred Qualifications

• Demonstrable proficiency configuring, operating, and troubleshooting MECM/SCCM (OSD, application packaging, software update deployments, collection management).
• Strong working knowledge of Linux administration, specifically Red Hat Enterprise Linux (RHEL), CLI troubleshooting, package management, daemon tuning, and SELinux enforcement.
• Solid experience with Windows Server (2019/2022) administration, Active Directory, GPO authoring/troubleshooting, and DNS.
• Experience with DoD vulnerability and compliance tooling: ACAS (Tenable/Nessus), SCAP Compliance Checker (SCC), and STIG Viewer (.ckl generation).
• Understanding of enterprise backup technologies, bare-metal server recovery, and hypervisor virtualization (Nutanix AHV, VMware).
• Excellent written communication skills for authoring Standard Operating Procedures (SOPs), weekly status reports, and technical troubleshooting documentation.
• Prior experience administering systems within DoD enterprise testing facilities, operational lab environments, or defense staging enclaves.
• Proficiency with PowerShell scripting and Linux Shell (Bash) scripting to automate routine administration, reporting, and deployment tasks.
• Hands-on experience managing and troubleshooting enterprise backup appliances (e.g., Cohesity) and application whitelisting tools (e.g., fapolicyd).
• Familiarity with Elastic Agent/Fleet management, LogRhythm, or enterprise SIEM architectures.
• Basic understanding of perimeter network components (firewalls, VPNs, F5 BIG-IP load balancers) and cloud hosting environments (AWS GovCloud).

What We Offer

• 401(k) Matching
• Company Events
• Dental Insurance
• Employee Recognition Programs
• Health Insurance
• Life Insurance
• Paid Time Off
• Parental Leave
• Performance Incentives
• Student Loan Repayment
• Tuition Reimbursement
• Vision Insurance This position will be posted for a minimum of 3 business days.

If a candidate has not been selected at that time, it will continue to be posted until a suitable candidate is selected or the position is closed. To be considered for this position, applicants must apply online by clicking "Apply" on the specific position on our careers site . All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran