Senior Systems Administrator - Vulnerability Remediation

Leidos LLC; Chantilly (VA); On-site; USD 116,000 - 210,000; Full time

Benefits offered by this job

Health and Wellness programs

Income Protection

Paid Leave

Retirement

Job summary

Leidos is seeking a Senior Systems Administrator to lead vulnerability remediation and system hardening for a primarily Windows-based enterprise. You will coordinate with the INFOSEC team, implement remediation actions, and help maintain ATO and system accreditation.

This Windows-heavy role benefits from Linux familiarity and requires Top Secret/SCI w/Poly, a degree, and extensive client/server experience. The position emphasizes proactive ownership and cross-team collaboration in Chantilly, VA.

Qualifications

• Clearance: Must have a Top Secret/SCI w/Poly to be considered
• 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
• Must pass customer-required and administered medical and psychological screening as a condition of employment (#MSBA)

Responsibilities

• 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)
• 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
• Research, validate, and recommend hardening changes with awareness of dependencies
• Implement and refine security configurations based on 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
• Design, implement, and manage Group Policy Objects (GPOs) to enforce security settings
• Evaluate and test policy changes for enterprise-wide impact
• Support domain-level security configurations and account policies
• Troubleshoot complex policy application issues and ensure consistent enforcement
• Support activities to achieve and maintain Authorization to Operate (ATO) and system accreditation
• Ensure remediation timelines meet accreditation and compliance requirements
• Provide detailed evidence and documentation for patching, hardening, and remediation
• Assist with audits, assessments, and validation of security controls
• Partner with INFOSEC and Client/Server teams to coordinate remediation efforts
• Communicate strategies, risks, and system impacts to stakeholders
• Participate in Windows patching activities with WUS team
• Validate patch applicability and remediation impact
• Support testing and post-deployment validation of Windows updates
• Troubleshoot update issues with server teams and ensure patch compliance

Skills

Vulnerability remediation

Group Policy management

Security remediation guidance

Education

Bachelor's degree

Master's degree

16 years of experience in lieu of degree

Tools

Windows

Linux

Job description

Leidos is seeking a Senior Systems Administrator to lead vulnerability remediation and system hardening for a primarily Windows-based enterprise. You will coordinate with the INFOSEC team, implement remediation actions, and help maintain ATO and system accreditation.

This Windows-heavy role benefits from Linux familiarity and requires Top Secret/SCI w/Poly, a degree, and extensive client/server experience. The position emphasizes proactive ownership and cross-team collaboration in Chantilly, VA.