Pentest Operator / Penetration Tester (Secret Clearance)

Pentest Operator
Secret Clearance required to start
Beltsville, MD - ONSITE

What You Will Do:
The Pentest Operator will support and lead pentesting engagements on High Value Asset (HVA) systems and enterprise security assessments, helping clients understand real-world attack paths, validate defensive controls, and prioritize remediation activities based on mission risk. The role includes internal and external network testing, web application testing, Active Directory assessment, adversary emulation, red team and purple team activities, vulnerability validation and reporting, and developing and presenting executive-level out-briefs.
The ideal candidate brings hands-on offensive security experience, strong client-facing communication skills, and the ability to translate technical findings into risk-based recommendations for system owners, security teams, and senior leaders. The candidate should be comfortable working in commercial and federal environments and collaborating with technical operators, analysts, engineers, and government stakeholders as required.

Key Responsibilities include:
• Performing penetration testing activities across internal networks, external networks, web applications, enterprise systems, cloud-connected systems, and mission environments.
• Supporting High Value Asset (HVA) cybersecurity assessments by identifying and communicating exploitable vulnerabilities, validating security control effectiveness, and determining risk to critical systems and data.
• Conducting network mapping, reconnaissance, vulnerability validation, exploitation, post-exploitation analysis, and documentation of attack paths within approved Rules of Engagement.
• Draft and/or provide input into Rules of Engagement, test plans and objectives, scope input and documentation, and revising and updating assessment procedures required to obtain management and stakeholder approval.
• Conduct external testing to evaluate what an outside attacker may be able to access, exploit, or exfiltrate within the approved scope.
• Conduct internal testing to evaluate risk posed by users or systems with different access levels, including privilege escalation, lateral movement, persistence, and Active Directory attack paths.
• Support red team and adversary emulation activities that simulate realistic threat behavior, including targeted access objectives, command-and-control simulation, crafted test artifacts, and controlled social engineering when authorized.
• Conduct web application testing for common vulnerability classes, including broken access control, authentication and authorization weaknesses, injection flaws, cross-site scripting, insecure configuration, and other OWASP Top 10 risks.
• Use offensive security tools and frameworks such as Kali Linux, Burp Suite, Metasploit, Nmap, Nessus, Wireshark, BloodHound, Impacket, Responder, Hashcat, John the Ripper, CrackMapExec, Cobalt Strike, Sliver, and similar tools within approved engagement boundaries.
• Drive vulnerability analysis and validation using manual techniques, automated tools, and custom scripts or proof-of-concept code where appropriate.
• Support purple team and detection validation activities by mapping attacker behavior to defensive telemetry, identifying detection gaps, and recommending improvements to SIEM, EDR, and incident response processes.
• Analyze logs, endpoint artifacts, and network telemetry during exercises or assessments to help validate whether adversary behaviors are detected and escalated appropriately.
• Write and present clear, evidence-based reports that document findings, affected assets, exploitability, business or mission impact, and prioritized remediation recommendations.
• Deliver technical and executive out-briefs to client stakeholders, including system owners, security operations teams, engineering teams, and senior leaders.
• Stay current on emerging attack techniques, offensive tooling, detection approaches, and federal cybersecurity requirements, and apply that knowledge to strengthen client security posture.

What You Will Need:
• An ACTIVE and MAINTAINED SECRET Federal or DoD security clearance.
• Bachelor’s degree in Cybersecurity, Information Technology, Computer Science, Information Systems, or a related field; additional relevant experience may be considered in lieu of degree.
• Minimum of FIVE (5) or more years of demonstrated hands-on experience in penetration testing, red team operations, adversary emulation, vulnerability assessment, application security testing, cyber operations, or related offensive security work.
• Experience performing internal and external network penetration testing, including reconnaissance, enumeration, exploitation, privilege escalation, lateral movement, and documentation of attack paths.
• Experience performing web application penetration testing using manual and automated techniques.
• Experience assessing Active Directory environments, Windows and Linux systems, and common enterprise network services.
• Experience using common penetration testing tools such as Burp Suite, Metasploit, Nmap, Nessus, Kali Linux, Wireshark, BloodHound, Impacket, Responder, Hashcat, John the Ripper, Cobalt Strike, Sliver, or similar tools.
• Experience developing test plans, documenting Rules of Engagement, tracking assessment activities, and producing formal penetration test reports.
• Ability to explain technical findings, attack paths, business impact, and remediation options to both technical and non-technical stakeholders.
• Strong written and verbal communication skills, including the ability to develop client-ready deliverables and executive-ready summaries.
• Ability to work independently, manage multiple priorities, and collaborate across multidisciplinary teams in complex federal environments.

What Would Be Nice To Have:
• An ACTIVE and MAINTAINED TOP SECRET Federal or DoD security clearance.
• Experience supporting HVA cybersecurity assessments or federal enterprise penetration testing programs.
• One or more relevant offensive security certifications such as OSCP, GPEN, GWAPT, GXPN, GRTP, PenTest+, CEH, GCIH, or similar certification.
• Experience with adversary emulation, purple team operations, detection engineering support, or validation of SIEM and EDR detection coverage.
• Experience with Cobalt Strike, Sliver, custom payload development, or command-and-control simulation in approved assessment environments.
• Experience with cloud security testing or assessment activities across AWS, Azure, or other cloud environments.
• Experience supporting incident response, threat hunting, or post-incident analysis.
• Experience creating proof-of-concept exploit examples for reports or live demonstrations in controlled, authorized environments.
• Experience mentoring junior penetration testers or leading small offensive security workstreams.
• Excellent oral and written communication and presentation skills.

#M1
#LI-VH1
Ref: #851-Rockville-S1

System One, and its subsidiaries including Joulé, ALTA IT Services, TeamPeople, and Mountain Ltd., are leaders in delivering outsourced services and workforce solutions across North America. We help clients get work done more efficiently and economically, without compromising quality. System One not only serves as a valued partner for our clients, but we offer eligible employees health and welfare benefits coverage options including medical, dental, vision, spending accounts, life insurance, voluntary plans, as well as participation in a 401(k) plan.

System One is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, age, national origin, disability, family care or medical leave status, genetic information, veteran status, marital status, or any other characteristic protected by applicable federal, state, or local law.