ISSE Cybersecurity Engineer for OT/UGS Lab Validation

Marathon TS; Ashburn (VA); On-site; USD 90,000 - 130,000; Full time

Job summary

Marathon TS seeks a cleared Cybersecurity Engineer / ISSE to work onsite in Ashburn, VA on a CBP contract. The role focuses on cybersecurity engineering, RMF/ATO evidence, vulnerability assessments, and lab validation for UGS and OT environments.

Responsibilities include scan readiness, telemetry and log identification with Splunk, vulnerability remediation, and documenting evidence for ATO and field alignment.

Qualifications

• Bachelor's degree in Cybersecurity, IT, CS, Engineering, or related field; equivalent experience may be considered.
• 5–7 years of experience in cybersecurity, security engineering, ISSE, vulnerability management, or security assessment roles.
• Experience supporting RMF, ATO, POA&M, security control evidence, vulnerability remediation, or continuous monitoring activities.
• Experience with vulnerability scanning tools such as Tenable Nessus or equivalent.
• Familiarity with SIEM/logging platforms such as Splunk and ability to identify useful telemetry/log sources.
• Experience assessing or supporting network-connected devices, embedded systems, OT, IoT, cameras, sensors, or field technology environments.
• Understanding of security hardening, firmware/software update validation, configuration baselines, change control, and risk documentation.
• Ability to document technical findings, limitations, test results, and security recommendations clearly for stakeholders.
• Ability to coordinate across cybersecurity, engineering, network, test, vendor, and program teams.
• Strong analytical, troubleshooting, and communication skills.
• Experience with Client/CBP environments, NIST, FISMA, RMF, or federal cybersecurity requirements preferred.

Responsibilities

• Support secure validation and documentation of OT and UGS before field alignment or production-like implementation.
• Support vulnerability scan readiness, asset identification, scan scope, credentials, limitations, and device impact considerations.
• Support SOC/Splunk readiness, telemetry availability, log sources, monitoring requirements, and security events.
• Validate firmware/software updates, review release notes, perform checksum/hash validation, track security impact.
• Document vulnerabilities, findings, limitations, remediation actions, compensating controls, and retest results for lab validation and ATO evidence.
• Provide security input to lab test plans, validation packages, and Phase 2 handoff materials.
• Assess whether proposed changes affect validated baselines, security posture, scanning, monitoring, or field alignment readiness.
• Coordinate with stakeholders to validate secure integration of UGS technologies.
• Support security documentation, including scan readiness checklists, security considerations, vulnerability tracking, and ATO evidence inputs.
• Provide security guidance to lab team members and support audits and evidence requests.
• Assist lab incident/security event handling by documenting events and coordinating with stakeholders.

Skills

Security engineering

ISSE

Vulnerability management

OT device assessment

Education

Bachelor's degree in Cybersecurity or related field

Tools

Tenable Nessus

Splunk

NIST RMF

Job description

Marathon TS seeks a cleared Cybersecurity Engineer / ISSE to work onsite in Ashburn, VA on a CBP contract. The role focuses on cybersecurity engineering, RMF/ATO evidence, vulnerability assessments, and lab validation for UGS and OT environments.

Responsibilities include scan readiness, telemetry and log identification with Splunk, vulnerability remediation, and documenting evidence for ATO and field alignment.