Penetration Tester III
SOSi · Washington, D.C.
📍 Washington, DC, usvia smartrecruitersPosted 2026-04-21
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Founded in 1989, SOSi is among the largest private, founder-owned technology and services integrators in the defense and government services industry. We deliver tailored solutions, tested leadership, and trusted results to enable national security missions worldwide.
Overview
SOSi is seeking a Penetration Tester III to support proactive cyber defense activities in alignment with our customer. This role is responsible for conducting penetration testing and red team activities, assessing security posture across enterprise environments, and supporting identification, validation, and reporting of vulnerabilities to improve cyber defense resilience.
Responsibilities
· Conduct penetration testing across enterprise systems, applications, and network environments
· Perform red team activities to evaluate security controls and identify exploitable weaknesses
· Support continuous penetration testing activities to assess evolving threats and vulnerabilities
· Conduct testing of IoT, mobile, and cloud environments
· Support High Value Asset (HVA) security assessments
· Apply testing methodologies and frameworks including MITRE ATT&CK, OSSTMM, OWASP, NIST, PTES, and ISSAF
· Identify, document, validate, and report vulnerabilities and recommended remediation actions
· Support cyber defense operations through coordination with security engineering, vulnerability management, and incident response teams
Experience: Five (5) to seven (7) years of penetration testing experience
Management or team lead experience
Experience performing continuous penetration testing
Experience conducting red team operations
Experience performing IoT, mobile, and cloud penetration testing
Experience supporting High Value Asset (HVA) assessments
Experience applying MITRE ATT&CK, OSSTMM, OWASP, NIST, PTES, and ISSAF methodologies
Education: Bachelor’s Degree
Certifications:
Required: GPEN or GXPN
CISA AES HVA Lead or Technical Lead , or ability to obtain Plus one of the following:
GRTP
CRTL
OSCP
CRTP
CMWAPT
CEPT
CPT
LPT
Clearance/Suitability : Secret (active)
Work Environment
Normal office conditions with potential to perform duties in deployed locations.
Core hours of operation are Monday through Friday, 0600 – 1700.
May be requested to work evenings and weekends to meet program and contract needs.
Working at SOSi
All interested individuals will receive consideration and will not be discriminated against for any reason.
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