Cybersecurity Engineer

D2 Technical Services•Saint Louis, MO

25d•Hybrid

About The Position

D2 Technical Services is seeking a Cybersecurity Engineer with an ACTIVE TS/SCI SECURITY CLEARANCE to join their team supporting an intelligence customer in Springfield, VA or Arnold, MO. This role is part of the Geospatial Services & Solutions (GSS) business area, focusing on providing high-quality, cost-effective solutions within a sophisticated enterprise environment. The cybersecurity engineer will be responsible for implementing and maintaining cybersecurity controls across various infrastructure environments, including Windows, Linux, network, virtualization, and cloud. Key activities include executing RMF continuous monitoring, implementing STIGs, remediating vulnerabilities, managing POA&Ms, and supporting Assessment & Authorization (A&A) efforts in accordance with NIST SP 800-53, ICD 503, and DoD security requirements. This is a hands-on technical position requiring expertise in system hardening, security finding remediation, enterprise security tool support, and collaboration with infrastructure teams to ensure a secure, compliant, and resilient operating environment.

Requirements

ACTIVE TS/SCI SECURITY CLEARANCE REQUIRED
Bachelor’s Degree in Computer Science, Engineering, Cybersecurity, Information Technology or a related technical discipline, or the equivalent combination of education, professional training or work experience.
5+ years of related experience in data security administration.
Experience implementing and supporting the Risk Management Framework (RMF) throughout the system lifecycle.
Strong knowledge of NIST SP 800-53, ICD 503, and DoD security policies.
Hands-on experience implementing, maintaining, and remediating Security Technical Implementation Guides (STIGs) across Windows, Linux (RHEL), network, virtualization.
Experience executing technical remediation activities for vulnerabilities identified through ACAS, STIG compliance reviews, and other vulnerability management tools.
Experience in writing, maintaining, and closing Plan of Action and Milestones (POA&Ms), including documenting remediation evidence and validating corrective actions.
Experience implementing and maintaining Assessment & Authorization (A&A) documentation and supporting RMF continuous monitoring activities.
Experience with security tools such as ACAS, HBSS, Carbon Black, Tanium, RedSeal, or equivalent.
Experience installing, hardening, deploying, documenting, and troubleshooting network perimeter security technologies.
Experience scripting with Unix/Linux (RHEL), Bash, Python, and PowerShell.
Strong analytical, troubleshooting, documentation, and communication skills.
Ability to work independently while managing multiple priorities.

Nice To Haves

Experience supporting NGA TESR environments.
Experience supporting Intelligence Community Assessment & Authorization processes.
Experience with security automation and Infrastructure-as-Code.
Experience with enterprise SIEM platforms such as Splunk or Elastic.
DOD 8570/8140 compliant certifications such as Security+, CISSP, CAP, or CASP+.

Responsibilities

Act as the representative of the Information System Security Manager (ISSM), ensuring compliance with DoD and Intelligence Community (IC) information security policies, procedures, and directives.
Support efforts to operate, maintain, and dispose of information system materials in accordance with RMF, NIST, ICD 503, and applicable security directives, policies, and System Security Plans (SSPs).
Implement and maintain Security Technical Implementation Guides (STIGs) across Windows, Linux (RHEL), network, virtualization, and cloud environments to ensure compliance with DoD security requirements.
Execute technical remediation activities to address security findings identified through ACAS, STIG reviews, vulnerability scans, and security assessments.
Manage assigned Plan of Action and Milestones (POA&Ms) by implementing technical solutions, validating remediation efforts, documenting completion evidence, and supporting POA&M closure.
Support RMF continuous monitoring activities by implementing required security controls, maintaining A&A documentation, and ensuring compliance with NIST SP 800-53 and ICD 503 requirements.
Generate and implement required cybersecurity awareness training, ensuring users understand their security responsibilities prior to system access.
Initiate protective and corrective measures when security incidents, vulnerabilities, or compliance issues have been identified.
Ensure IA hardware, software, and operating systems comply with approved security configuration guides and organizational security baselines.
Implement and enforce IA policies and procedures as defined by RMF authorization packages and A&A documentation.
Ability to work on multiple projects simultaneously in a dynamic, fast-paced, team-oriented environment.
Perform Operations & Sustainment (O&S) functions for enterprise network security infrastructure, including firewalls, web gateways, mail gateways, IDS/IPS, load balancers, performance monitoring tools, and management systems.
Perform maintenance, hardening, patching, and advanced configuration of security infrastructure to protect enterprise networks from emerging cyber threats.
Support and secure Cloud Infrastructure, including AWS-based technologies.
Utilize enterprise security tools such as ACAS, HBSS, Carbon Black, Tanium, RedSeal, and related cybersecurity platforms.
Conduct forensic network traffic and log analysis to investigate incidents, isolate issues, and respond to analyst alerts.
Respond to escalated cybersecurity and infrastructure troubleshooting requests.
Maintain and administer network infrastructure standards, documentation, and fault-tolerant configurations.
Present monitoring testing, compliance, and remediation results and reports as required.
Perform and support integration testing, security validation, and operational readiness activities.
Develop automation and scripting solutions using Powershell, Bash, Python, or similar languages to improve security operations and compliance.
Collaborate with systems, network, and cloud engineering teams to implement secure architectures and operational best practices.
Participate in special projects as required.