Penetration Tester (Mid+/ Senior)

UnderDefense Inc.; United States; Hybrid; USD 120,000 - 190,000; Full time

Benefits offered by this job

Growth opportunities

Competitive salary

Brilliant team

Flexible working hours

Paid vacation and sick-leave

Internal training & conferences

English courses

Work-rest balance

Job summary

UnderDefense Inc. is seeking a Mid+/Senior Penetration Tester to lead and execute Red Team engagements across mobile, desktop, and IoT environments. You will craft implants and exploits for Windows/Mac when required, assess cloud infrastructure, and report findings with prioritized business risks.

Ideal candidates hold OSCP/OSEP or equivalent certifications, can code in Python/C/C++/.NET, and present clear client reports. Flexible hours expected in a dynamic security team.

Qualifications

• Hands-on Red Team experience across multiple platforms.
• Strong knowledge of C2 frameworks and exploit development.
• Proven internal AD and cloud testing capabilities.

Responsibilities

• Independently own End-to-End Red Team engagements.
• Develop custom implants/beacons when needed.
• Deliver detailed client reports with risk and recommendations.
• Share knowledge through internal sessions and trainings.
• Collaborate with teammates to improve testing capabilities.

Skills

Red Team ops

AD/Active Directory tests

OPSEC techniques

Mobile/Desktop/IoT testing

Cloud security testing

Business logic flaws

AI tooling integration

Report presentation

Team collaboration

Education

OSCP/CEH/OSEP or equivalent

Tools

Python

C/C++

.NET

Job description

Penetration Tester (Mid+/ Senior)

About company

UnderDefense is a fast-growing company that safeguards businesses around the globe from cybersecurity threats. We are a globally top-ranked firm by Gartner and Clutch, provide cyber resiliency consulting and technology-enabled services to anticipate, manage and defend against cyber threats. We empower clients to predict, prevent, detect, and respond to threats.
We work with 122 clients in more than 20 countries. We have already detected 38K vulnerabilities before hackers tried to exploit them. We are passionate about making the Internet a Safer to people and businesses.

We are looking for bright and self-motivated individuals to join our technical team. Someone who is passionate about Security as we are.

Qualifications:

• Red Team (core):hands-on experience with C2 frameworks; base in exploit development and writing implants/beacons for C2.
• Deep Internal / Active Directorypenetration testing.
• OPSEC techniquesand understanding of how SOC and defensive mechanisms work – and how to evade them.
• Mobile, Desktop, IoT (willing to cover):general testing techniques; understanding of Windows/Linux/MacOS/iOS/Android internals and system-level vulnerabilities; for IoT – protocols plus basic hardware skills (disassemble a board, solder).
• Cloud:understanding of cloud infrastructure, privileges and related attack vectors.
• Business-logic vulnerabilities:proven experience and breadth in finding non-standard logic flaws.
• Deep adoption of AI tooling(own setups, MCP; AI integrated into the workflow – not surface-level use).
• Englishsufficient to independently present a report to the client and answer questions.
• Webis not the core focus but assumed by default at this level.

Preferred Experience:

OSCP / CRTO / OSEP or other related offensive-security certifications; ability to code in Python, C/C++, .NET or similar.

Responsibilities:

• Independently own and deliver Red Team engagements end-to-end (planning, execution, reporting, client delivery).
• Take on complex projects across Mobile, Desktop and IoT
• Develop custom implants, beacons and exploits for Windows/Mac when engagements require it.
• Create detailed reports explaining technical and logical findings, business risk and prioritized recommendations.
• Share expertise: run lessons-learned, internal lectures and knowledge sharing
• Act as a role model by example – take the initiative, dig in, take ownership.
• Collaborate closely with the team and contribute to continuous improvement of teampentest capabilities.
• Think outside the box and simulate real adversarial approaches.

What we offer:

• Growth, really fast growth
• Good salary + really challengeable projects
• Brilliant Team
• Flexible working hours
• Paid vacation and sick-leaves
• Internal training and workshop (conferences, workshops, training, etc.)
• English courses
• Work-rest balance support ( foosball, workout station)