Senior ISSO for Federal Systems - RMF, ATO & Cloud

tharros; Washington (District of Columbia); On-site; USD 120,000 - 180,000; Full time

Job summary

Tharros is seeking a Senior Information Systems Security Officer to support a DHS Intelligence and Analysis cybersecurity program in the National Capital Region. This role will oversee ISSO operations across a complex Federal environment, including RMF activities, ATO package maintenance, and cloud and on‑premises systems.

The ideal candidate is hands-on, maintains authorization evidence, and collaborates with system owners, ISSOs, ISSMs, developers, and assessors to address vulnerabilities and

Qualifications

• Hands-on ISSO with ability to maintain authorization evidence and artifacts.
• Coordinate with system owners, ISSOs, ISSMs, and engineers to address vulnerabilities.
• Experience supporting RMF processes across federal information systems.

Responsibilities

• Perform ISSO duties for assigned Federal information systems.
• Support RMF activities, including system categorization and control implementation.
• Maintain SSPs, POA&Ms, risk exceptions, and contingency plans.
• Create and monitor ATO packages in GRC tools.
• Support POA&M development, remediation tracking, and reporting.
• Collaborate with owners, ISSOs, ISSMs, developers, and assessors to address vulnerabilities and remediation actions.
• Review vulnerability scans and support continuous monitoring.
• Support audit log review and documentation of follow-up actions.
• Ensure assigned systems remain aligned with applicable cybersecurity policies, procedures, and decommissioning requirements.
• Support quarterly cybersecurity performance and compliance reporting.
• Provide ISSO support across hybrid environments (classified/unclassified, cloud, DevSecOps).
• Support security for Linux, Windows, open-source OS, and cloud platforms.
• Support Cross Domain Solution security governance, assessment, and authorization.
• Help improve ISSO workflows, evidence management, POA&M tracking, continuous monitoring, and risk reporting through automation.
• Translate compliance status, vulnerability data, and remediation progress into updates for leadership.

Tools

Archer

eMASS

Xacta

ACAS

Tenable.sc

Splunk

GitLab

Axonius

STIG/SCAP validation

AWS

Azure

Microsoft 365

Job description

Tharros is seeking a Senior Information Systems Security Officer to support a DHS Intelligence and Analysis cybersecurity program in the National Capital Region. This role will oversee ISSO operations across a complex Federal environment, including RMF activities, ATO package maintenance, and cloud and on‑premises systems.

The ideal candidate is hands-on, maintains authorization evidence, and collaborates with system owners, ISSOs, ISSMs, developers, and assessors to address vulnerabilities and