Leidos has a current job opportunity for a Tenable RHEL ACAS Administrator on the DISA GSM-O program in Alexandria, VA. An active Secret Security Clearance is required prior to start.

Position Summary:  

This position serves as a member of the Tenable ACAS team responsible for operating and maintaining the DISA J6 Pentagon’s Assured Compliance Assessment Solution (ACAS) program. This position supports timely and accurate scanning and reporting per DISA J6 Pentagon and DoD policies and orders. Activities that this position will execute include system administration for all Tenable ACAS Red Hat Enterprise Linux (RHEL) servers, performing systems analysis, modifying / updating, troubleshooting Tenable applications based on results of analysis, deployment of application and tools, performing testing of deployed application and tools, and communicating updates to Tenable ACAS Lead and customers as required. 

Responsibilities include:

Serve as an integral member of a team of Tenable specialists supporting various organizations across the National Capital RegionComplete the following key functions for Tenable deployments across DISA J6 Pentagon’s area of responsibility:Manage the RHEL servers that are part of the Tenable ACAS for DISA J6 Pentagon.Provide performance tuning to systems and troubleshoot Tenable components which span a large and complex environmentProvide solution engineering support to ensure systems and components meet current and future standardsInstall updates to Tenable software as released and in compliance with STIG requirementsDeploy, maintain, and perform tuning of Tenable scanners to meet current and future needsDeploy, maintain, and perform tuning of Tenable Nessus Managers and Nessus Agents to meet current and future needsDevelop / create, deploy, and manage Tenable scan configurationsConduct scans and provide detailed reporting to the DISA J6 Pentagon leadership as well as scanned organizationsEnsure that the ACAS scanners and Security Center are operational and reporting properlyAssist customers in resolving ACAS issues, make recommendations as needed    Perform monthly vulnerability scans and create repositories, queries, and dashboards as necessary to ensure vulnerability report information is availableInvestigate false positives or potentially confusing scan data resultsDevelop tracking mechanism for false positives and track false positives until the finding is corrected; provide results upon resolution

Basic Qualifications:

Bachelor's degree and 12+ years of prior IT experience including experience working with RHEL OS, Tenable Security Center and Tenable Nessus agents within the DoD environment. Additional work experience or Cyber courses/certifications may be substituted in lieu of degree.Active Secret clearance or higher (program can support up to TS/SCI)DoD 8570 IAT II certification is required prior to start. Current RHEL certification or ability to obtain certification within 6 months of start dateExperience running ACAS on Red Hat Enterprise Linux (RHEL)Hands-on experience with general RHEL administration and troubleshootingDemonstrated experience with multiple network security zones, subnetting, VRFs, and VLANsMotivated self-starter with strong written and verbal communication skills, and the ability to create complex technical reports on analytic finding.Strong analytical and troubleshooting skills.    

Preferred Qualifications:

Cybersecurity experience (Protect, Detect, Respond and Sustain) within a Computer Incident Response organization.Advanced understanding of the life cycle of cybersecurity threats, attacks, attack vectors and methods of exploitation with an understanding of intrusion set tactics, techniques and procedures (TTPs).Experience with malware analysis concepts and methods.Motivated self-starter with strong written and verbal communication skills, and the ability to create complex technical reports on analytic findings.Familiarity or experience in Intelligence Driven Defense, Cyber Kill Chain methodology, and/or MITRE ATT&CK framework.

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Original Posting:August 13, 2025

For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.

Pay Range:Pay Range $126,100.00 - $227,950.00

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.