Millennium is proud to be part of the Markon Solutions family of companies a network of specialized organizations united in support of critical national security missions. This partnership strengthens our ability to deliver results by expanding our technical depth, operational reach, and access to a broader bench of proven experts, ensuring our customers continue to receive best-in-class cybersecurity support.

For more than two decades, Millennium has operated at the forefront of cybersecurity. Our elite team of over 300 professionals brings an unmatched record of performance across Red Team Operations, Defensive Cyber Operations, Software Engineering, and Technical Engineering. As home to the largest contingent of contracted Red Team operators supporting the Department of Defense, Millennium delivers unparalleled threat intelligence and battle-tested expertise to both DoD and federal civilian customers.

Millennium is an equal opportunity employer and does not discriminate or allow discrimination on the basis of race, color, religion, gender, age, national origin, citizenship, disability, veteran status or any other classification protected by federal, state, or local law.

Millennium is seeking a Principal Cyber Engineer/ Advanced Cyber Operator to support the Director, Operational Test and Evaluation (DOT&E) Cyber Assessment Program. This position provides integrated cyber threat, intelligence, and mission assurance analysis in support of operational test and evaluation activities across Government-designated organizations and mission environments. The candidate must have an active TS/SCI Clearance. This job is available at multiple locations.

The Principal Cyber Engineer / Advanced Cyber Operator supports the Cyber Assessment Program by conducting advanced adversarial emulation and penetration testing across government networks and systems. This role executes full-spectrum Red Team operations using real-world threat tactics, develop custom tools and exploits, and provides expert-level security engineering guidance to Government stakeholders. The position blends hands-on offensive cyber operations with strategic assessment, reporting, and collaboration with defensive teams to improve enterprise cyber resilience.

Key Duties:

Offensive Cyber Operations & Red Teaming

• Execute Red Team and adversarial emulation engagements from planning through reporting using real-world threat TTPs
• Conduct penetration testing against applications, networks, operating systems, and cloud environments
• Perform OSINT, vulnerability discovery, exploitation, lateral movement, persistence, and command-and-control operations
• Develop payloads, scripts, and tools for exploitation, evasion, and post-exploitation activities
• Safely employ attacker TTPs in sensitive environments in accordance with Standing Ground Rules and policies
• Evade defensive controls (e.g., EDR, AV, behavioral detection systems) to meet engagement objectives
• Emulate Advanced Persistent Threat (APT) actors using MITRE ATT&CK–aligned methodologies

Tool Development & Research

• Rapidly develop domain-specific tools and scripts in high-tempo environments
• Research emerging threats, exploitation techniques, and vulnerabilities
• Design and configure representative test environments
• Build innovative accelerators and frameworks to improve Red Team velocity and scalability

Security Engineering & Assessment

• Analyze applications and systems to identify design and implementation flaws
• Perform source code review, reverse engineering, and exploit research
• Develop security testing strategies to assess effectiveness of controls
• Provide remediation recommendations and risk mitigation strategies
• Demonstrate findings and collaborate with Blue Teams to improve detection

Reporting & Communication

• Document exploitation activities and vulnerabilities clearly and accurately
• Produce technical and executive-level reports and briefings
• Communicate engagement objectives, risks, and results to technical and non-technical audiences
• Support training events, exercises, and demonstrations

Program & Stakeholder Support

• Provide subject matter expertise to Government personnel
• Collaborate with cross-functional security teams
• Support compliance with Red Team policies and accreditation requirements
• Assist with business development activities including:
  • Technical interviews
  • Proposal support
  • Technical documentation
  • Color team reviews

• Candidate must have an active TS/SCI Clearance.
• Bachelor’s degree in Computer Science, Engineering, Cybersecurity, or related technical discipline (or equivalent experience) and 8–10+ years of practical offensive cyber or Red Team experience
• One or more of the following certs are required: OSCP, OSCE/3, GXPN. Preferred Qualifications: Master’s degree in Cybersecurity or Computer Science. 10+ years supporting DoD OCO or DCO missions. Experience supporting TSMO, NSA, Air Force or Navy Red Teams. Expertise in one or more: Active Directory, Software Development, Incident Response, Cloud Infrastructure

• Must be comfortable with prolonged periods of sitting at a desk and working on a computer.
• Must be able to lift up to 10-15 pounds at a time.

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