Penetration Tester

Ncounter Limited; England; Hybrid; GBP 60,000 - 80,000; Part time

Job summary

A cybersecurity consulting firm in the UK seeks a Red Team Operator to engage in true adversary simulation within Defence environments. This role involves executing penetration tests, assessing potential threats, and producing technical reports with remediation guidance. Candidates should have proven experience in offensive cyber operations and hold either SC or DV clearance. This position offers a significant opportunity to impact Defence work and build ongoing engagements.

Qualifications

• Proven experience within Defence or regulated environments.
• Active SC or DV clearance, ideally DV.
• Ability to operate confidently onsite.

Responsibilities

• Supporting confirmation of scope sessions and contributing to test plans.
• Designing and executing adversary simulation activity.
• Exploiting networks to elevate privileges and move laterally.
• Simulating threat actor behaviour including data exfiltration.
• Producing high quality technical and management reports.
• Participating in technical replays with Blue Teams.

Skills

Red Team or offensive cyber experience

Understanding of insider threat scenarios

Technical report writing

Education

Relevant certifications (OSCP, CRTO, GIAC)

Job description

Red Team Operator / Penetration Tester (SC or DV Cleared)

Ncounter is supporting a specialist Defence consultancy on two upcoming Red Team engagements within a major Defence programme. These are initial 3-month contracts, with a strong likelihood of extension, forming the first wave of a wider pipeline of similar work expected over the next 12 months.

The focus of these engagements is true adversary simulation. Working from standard user credentials, you will help define and execute realistic Red Team activity, assessing how an attacker could infiltrate, move laterally, elevate privileges, and exfiltrate data within sensitive environments. You will play a key role in shaping the technical approach, rather than simply delivering pre‑defined tests.

Work will be based primarily out of SW sites or nearby Defence related sites, with an expectation of 2 to 3 days per week onsite.

Key responsibilities include:

• Supporting confirmation of scope sessions and contributing to detailed Red Team test plans


• Designing and executing adversary simulation and penetration testing activity against Defence systems


• Exploiting networks to enumerate services, elevate privileges, and move laterally


• Simulating advanced threat actor behaviour including command and control and data exfiltration


• Producing high quality technical and management level reports with clear remediation guidance


• Participating in technical replays with Blue Teams to support detection and mitigation

To be considered, you will bring:

• Proven Red Team or offensive cyber experience within Defence or similarly regulated environments


• Active SC or DV clearance, ideally DV


• Strong understanding of insider threat scenarios and post‑compromise activity


• Relevant certifications such as OSCP, CRTO, or GIAC, or equivalent hands‑on expertise


• The ability to operate confidently onsite within Defence environments

If you are an experienced Red Team operator looking to be involved in high impact Defence work with genuine follow‑on opportunities, get in touch with Ncounter for a confidential discussion