Penetration Tester

83zero Ltd; United Kingdom; Remote; GBP 80,000 - 105,000; Full time

Job summary

83zero Ltd is hiring an Offensive Security Consultant/Penetration Tester for a 12-month contract. The role involves delivering penetration testing, red team and adversary simulation engagements for a leading global cyber security vendor, working fully remotely within an enterprise context.

You will conduct testing across networks, cloud, web and mobile, perform AD security assessments, and contribute to detailed customer-facing reports with remediation guidance.

Qualifications

• Hands-on penetration testing across enterprise networks, cloud, web apps and APIs.
• Plan and execute red team and purple team exercises.
• Identify vulnerabilities and demonstrate risks with PoC exploits.
• Active Directory security assessments and exploitation testing.
• Support phishing simulations and adversary simulations.
• Produce detailed reports and remediation recommendations.

Responsibilities

• Conduct hands-on penetration testing across enterprise networks, cloud environments, web applications, APIs and mobile platforms.
• Plan and execute red team and purple team exercises, aligned with MITRE ATT&CK framework.
• Identify vulnerabilities, develop PoC exploits and demonstrate security risks.
• Conduct Active Directory security assessments and exploitation testing.
• Support phishing simulations, social engineering and other adversary activities.
• Produce detailed technical reports and communicate findings to customers.

Skills

Penetration testing

Red teaming

Adversary simulation

Customer-facing

MITRE ATT&CK

Education

OSCP/OSWP/GWAPT equivalents

Tools

Burp Suite

Metasploit

Cobalt Strike

Nmap

BloodHound

Empire

Job description

Offensive Security Consultant/Penetration Tester

£500 per Day | Inside IR35 | Fully Remote | 12-Month Contract

We are working with a leading global cyber security vendor looking for an experienced Offensive Security Consultant/Penetration Tester to join their Professional Services team on an initial 12-month contract.

This is an excellent opportunity to work on complex enterprise security engagements, delivering penetration testing, adversary simulations and red team exercises for customers across a range of industries.

Key Responsibilities

• Conduct hands-on penetration testing across enterprise networks, cloud environments (AWS, Azure, GCP), web applications, APIs and mobile platforms.
• Plan and execute red team and purple team exercises, aligned with frameworks such as MITRE ATT&CK.
• Identify vulnerabilities, develop proof-of-concept exploits and demonstrate potential security risks.
• Conduct Active Directory security assessments and exploitation testing.
• Support phishing simulations, social engineering and other adversary simulation activities.
• Produce detailed technical reports, communicate findings to customers and recommend remediation strategies.
• Work directly with enterprise customers and internal Professional Services teams.

Skills & Experience

• Strong hands-on experience in penetration testing, offensive security or red teaming.
• Practical experience with tools such as Burp Suite, Metasploit, Cobalt Strike, Nmap, BloodHound and Empire.
• Scripting experience using Python, PowerShell, Bash or Go.
• Good understanding of Active Directory, cloud security, container security and web/API vulnerabilities.
• Knowledge of MITRE ATT&CK and OWASP Top 10.
• Experience delivering customer-facing security assessments and presenting technical findings.
• Certifications such as OSCP, OSEP, OSWE, OSCE, GPEN, GWAPT or GPEN-equivalent qualifications would be advantageous.

Contract Details

• Rate: £500 per day
• IR35: Inside IR35
• Duration: Initial 12 months
• Location: Fully Remote
• Client: Leading Global Cyber Security Vendor