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.
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 career experience in lieu of degree.
- Client/Server experience.
- Linux and Windows
- You will be required to pass both a customer required and administered medical and psychological screening, as a condition of employment
Original Posting:June 4, 2026
Pay Range:Pay Range $116,350.00 - $210,325.00
The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.
