Senior Microsoft Systems Administrator

Seneca Resources; Montgomery (AL); On-site; USD 97,000 - 132,000; Full time

Job summary

Seneca Resources is seeking a Senior Microsoft Systems Administrator in Montgomery, AL to lead Windows hardening under NIST 800-53 controls. You will implement baselines, enforce access controls, and monitor compliance using AD, Intune, SCCM/MECM, Azure AD, Defender, and related tools.

Responsibilities include GPO management, baseline configurations, and automation with PowerShell. Candidates should have 4+ years of enterprise Windows experience and strong security controls knowledge.

Qualifications

• 4+ years of hands-on Windows server/workstation administration.
• Experience implementing NIST SP 800-53 controls on Microsoft platforms.
• Proficiency with AD, Group Policy, PowerShell, SCCM/MECM, Intune.
• Understanding 800-53 control families (AC, AU, CM, IA, SC).
• Experience with hardening baselines and least-privilege.
• Familiarity with Nessus/Tenable for compliance.

Responsibilities

• Harden Windows Server/Workstations per NIST 800-53 Rev.5.
• Manage GPOs, baselines, and Intune policies to enforce configurations.
• Configure host-based firewalls, MFA, privileged account management.
• Administer AD, SCCM/MECM, Intune, Azure AD/Entra ID, Defender.
• Develop PowerShell scripts for automation and compliance checks.
• Document SSP, POA&M, and evidence for controls.

Skills

Windows server administration

PowerShell scripting

Security controls understanding (NIST

Tools

Active Directory

Group Policy

SCCM/MECM

Intune

Azure AD/Entra ID

Defender for Endpoint

Azure Policy

Job description

Position Title: Senior Microsoft Systems Administrator

Location: Montgomery, Alabama

Rate: $55/hr on W2

Job Summary

We are seeking a Senior Microsoft Systems Administrator to lead a project to harden Windows servers and workstations in compliance with NIST SP 800-53 security controls. This role focuses on implementing configuration baselines, enforcing access controls, and continuous monitoring. This position requires strong technical expertise in Microsoft technologies combined with practical knowledge of cybersecurity standards.

Key Responsibilities

• Install, configure, harden, patch, and maintain Windows Server (2019/2022+) and Windows 10/11 workstations in accordance with NIST SP 800-53 Rev. 5 controls.
• Implement and validate security controls across families including Access Control (AC), Configuration Management (CM), Identification & Authentication (IA), Audit & Accountability (AU), System & Communications Protection (SC), and others relevant to endpoint/server platforms.
• Manage Group Policy Objects (GPOs), security baselines, and Intune/Microsoft Endpoint Manager policies to enforce 800-53-aligned configurations (e.g., password policies, account lockout, least privilege, firewall rules, AppLocker, BitLocker).
• Perform hardening tasks including:
• Configuring host-based firewalls and intrusion detection/prevention
• Implementing multi-factor authentication and privileged account management
• Enabling cryptographic protections for data at rest/transit
• Removing unnecessary services, features, and default accounts
• Administer Microsoft tools for compliance: Active Directory, Microsoft Endpoint Configuration Manager (SCCM/MECM), Microsoft Intune, Azure AD/Entra ID, Defender for Endpoint, and Azure Policy (where hybrid/cloud-integrated).
• Document system security plans (SSP), control implementation details, POA&Ms, and evidence for NIST 800-53 controls during the project.
• Develop PowerShell scripts for automation of compliance checks and reporting.

Required Qualifications

• 4+ years of hands-on experience administering Windows servers and workstations in enterprise environments.
• Demonstrated experience implementing NIST SP 800-53 security controls on Microsoft platforms.
• Proficiency with Microsoft administration tools: Active Directory, Group Policy, PowerShell, SCCM/MECM, Intune, Defender suite.
• Understanding of key 800-53 control families as applied to endpoints/servers (AC, AU, CM, IA, SC, SI, etc.).
• Experience with hardening techniques, baseline configuration management, and least-privilege principles.
• Familiarity with compliance tools (Nessus/Tenable or similar).
• Strong scripting skills (PowerShell preferred) for automation and compliance checks.
• About Seneca Resources
• At Seneca Resources, we are more than just a staffing and consulting firm, we are a trusted career partner. With offices across the U.S. and clients ranging from Fortune 500 companies to government organizations, we provide opportunities that help professionals grow their careers while making an impact.
• When you work with Seneca, you’re choosing a company that invests in your success, celebrates your achievements, and connects you to meaningful work with leading organizations nationwide. We take the time to understand your goals and match you with roles that align with your skills and career path. Our consultants and contractors enjoy competitive pay, comprehensive health, dental, and vision coverage, 401(k) retirement plans, and the support of a dedicated team who will advocate for you every step of the way.
• Seneca Resources is proud to be an Equal Opportunity Employer, committed to fostering a diverse and inclusive workplace where all qualified individuals are encouraged to apply.