Host Security System Administrator; TS​/SCI Security Clearance

Position: Host Based Security System Administrator (TS/SCI) with Security Clearance
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- Description Mission One:
Land The Job. Mission Two:
Outdo What's Next. Come #Outsmart Outdo at Leidos! Leidos is seeking an experienced a TS/SCI cleared Host-Based Security System (HBSS) Administrator to support the management, configuration, and maintenance of endpoint security infrastructure across Department of Defense (DoD) and federal government networks. The ideal candidate brings hands-on experience with McAfee ePolicy Orchestrator (ePO) and the Trellix Security Platform Suite and operates comfortably within a compliance-driven environment governed by DoD standards.

The position requires to perform job duties onsite at Langley Air Force base, VA.

Roles and Responsibilities
* Manage, deploy, and maintain HBSS/Trellix endpoint protection technologies across enterprise networks to monitor, detect, and respond to security events.
* Configure and fine-tune HBSS modules including Host Intrusion Prevention System (HIPS), Data Loss Prevention (DLP), and Policy Auditor.
* Implement and maintain DISA Security Technical Implementation Guides (STIGs) to ensure systems remain audit-ready for command inspections and authorization reviews.
* Oversee OS and application patch deployments through McAfee ePO; track vulnerabilities and support Information Assurance (IA) compliance efforts.
* Identify and isolate system anomalies; assist with incident response activities and coordinate with engineering and security operations teams to resolve HBSS point-product issues.
* Monitor server and network health, generate compliance and exception reports, and brief leadership on system status as required.
* Support Authority to Operate (ATO) activities by maintaining accurate system documentation, POA&Ms, and security baselines.
* Coordinate with system owners and the ISSM/ISSO to ensure endpoint policies align with organizational security requirements. Basic Qualifications
* Bachelor’s degree in Computer Science, Cybersecurity, Information Technology, or a related field with 4-8 years of directly applicable experience. Additional years of relevant experience will be considered in lieu of degree.
* Must have a DoD TS/SCI Clearance.
* Certification:
DoD 8570/8140-compliant certification at IAT Level II or higher — CompTIA Security+ CE required at a minimum.
* Work will occur at government facilities in the Hampton Roads area. Travel may be required to CONUS and OCONUS locations

* Experience:

3–5 years of hands-on experience administering HBSS, McAfee ePO, or the Trellix Security Platform Suite in a DoD or federal government environment, including deployment and management in a predominantly Red Hat Enterprise Linux (RHEL) environment.
* Technical Knowledge:
Working knowledge of DISA STIGs, NIST SP 800-53, and DoD IA policies and regulations; familiarity with Linux-specific HBSS agent deployment, configuration, and troubleshooting.
* System Administration:
Proficiency in Red Hat Enterprise Linux (RHEL) administration — including RPM package management, SELinux policy, systemd services, and security baseline configuration — as well as Windows Server administration and OS patching.

Preferred Qualifications
* Additional certifications such as CISSP, CISA, CEH, or vendor-specific ePO/Trellix training and certification.
* Proficiency in scripting and automation (e.g., Bash, Power Shell, Python)
* Experience with Assured Compliance Assessment Solution (ACAS) / Tenable Nessus for vulnerability scanning and remediation tracking.
* Familiarity with Security Information and Event Management (SIEM) tools and integration with HBSS/Trellix event data.
* Experience supporting RMF Authorization packages, including development of System Security Plans (SSPs) and continuous monitoring activities.
* Red Hat certifications such as RHCSA or RHCE, or equivalent demonstrated Linux administration experience in a security-focused role.
* Knowledge of scripting (Bash, Python, or Power Shell) for automating HBSS agent deployments, compliance checks, or ePO reporting tasks across mixed OS environments.
* Prior experience in a SOC, NOC, or Cyber Defense environment supporting 24/7 operations.
* Familiarity with cloud-based endpoint…