Systems Administrator - Vulnerability Mitigation

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At Leidos we deliver innovative solutions through the efforts of our diverse and talented people who are dedicated to our customers' success. We empower our teams, contribute to our communities, and operate sustainable. Everything we do is built on a commitment to do the right thing for our customers, our people, and our community. Our Mission, Vision, and Values guide the way we do business.

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Leidos Intelligence Group uses a wide range of capabilities in Digital Modernization, Mission Software Systems, and enabling technologies like Artificial Intelligence and Machine Learning to support our customers' mission to defend against evolving threats around the world. Our team's focus is ensuring our intelligence customers have the right tools, technologies, and tactics to keep pace with an ever-evolving security landscape and succeed in their pursuit to protect people and critical assets.

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We are seeking a Senior Systems Administrator to lead execution of vulnerability remediation and system hardening activities across a primarily Windows-based enterprise environment. This role works in close coordination with the Information Security (INFOSEC) team, which is responsible for vulnerability identification and prioritization. The Senior Systems Administrator is responsible for researching, validating, and implementing remediation actions, including assessing potential system impacts prior to deployment.

This role plays a key part in achieving and maintaining system Authorization to Operate (ATO) and ongoing system accreditation efforts. While this is a Windows-heavy position, familiarity with Linux systems and basic administration is beneficial. We are looking for a proactive, execution-focused individual who takes ownership of assigned responsibilities and consistently drives remediation efforts to completion with minimal oversight.

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Vulnerability Remediation Execution

* Lead remediation of vulnerabilities based on direction and prioritization from the INFOSEC team

* Research remediation options and assess potential system and operational impacts prior to implementation

* Translate vulnerability findings into system-level fixes (patching, configuration changes, registry updates, etc.)

* Execute and guide remediation efforts across Windows systems, with support for Linux where applicable

* Independently drive remediation efforts to completion and remove blockers as they arise

* Track remediation progress and provide clear status reporting to stakeholders

System Hardening & Configuration

* Research, validate, and recommend hardening changes with full awareness of system and application dependencies

* Implement and refine security configurations based on established baselines and INFOSEC guidance

* Disable or restrict insecure protocols, ports, and services (e.g., SMBv1, legacy TLS)

* Configure and maintain secure cipher suites and encryption standards

* Apply and interpret STIGs, CIS Benchmarks, or organizational hardening standards across Windows systems, with awareness of equivalent practices in Linux environments

Group Policy & Active Directory

* Design, implement, and manage Group Policy Objects (GPOs) to enforce security settings

* Evaluate and test policy changes to understand enterprise-wide impact prior to deployment

* Support domain-level security configurations and account policies

* Troubleshoot complex policy application issues and ensure consistent enforcement

Compliance & Reporting

* Support and contribute to activities required to achieve and maintain Authorization to Operate (ATO) and system accreditation

* Ensure systems meet remediation timelines aligned with accreditation and compliance requirements

* Provide detailed evidence and documentation for patching, hardening, and remediation activities

* Assist with audits, assessments, and validation of security controls

Collaboration

* Partner with INFOSEC and Client/Server teams to coordinate and execute remediation efforts

* Communicate implementation strategies, risks, and system impacts to technical stakeholders

Windows Patching & Updates

* Participate in Windows patching activities in coordination with the WUS team

* Validate patch applicability and remediation impact prior to deployment

* Support testing and post-deployment validation of Windows updates

* Troubleshoot complex update issues in collaboration with WUS and server teams

* Ensure systems meet patch compliance requirements as defined by organizational standards

Required Qualifications:

* Clearance:
Must have a Top Secret/SCI w/Poly to be considered

* Must have a Bachelor's degree and at least 12 years of experience OR a Master's degree and at least 10 years of prior relevant experience preferred OR 16 years of relevant…