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Alex Thomas

Available for contract

Manchester --:-- UK

Seniorpenetration tester,ready for hire.

I’m Alex Thomas, a Principal-level penetration tester, AI pentester and CHECK Team Leader. For ten years I’ve delivered security testing for UK Government and large enterprise. I offer web and API penetration testing, cloud and Kubernetes security assessments, AI-assisted and adversary-led testing, CHECK infrastructure and internal network testing, DevSecOps and secure code review, mobile and wireless testing, and testing leadership including scoping, report QA and mentoring.

Start a conversationWhat I test

Credentials

  • OSCP
  • CHECK Team Leader
  • CSTL Infrastructure
  • Principal (PriCSP)
Tenure
10yearsOffensive security, from graduate tester to CHECK Team Leader
Selected
1 of 8Senior UK Government testers chosen for a national AI-assisted security pilot
Disclosed
14,000+User records exposed by a single auth bypass I reported
Coverage
Multi-cloudSecurity testing across the major cloud providers and managed Kubernetes

01AI pentesting

One of eight senior testers asked to put AI pentesting to the test.

In 2026 I was selected from across UK Government departments to help evaluate AI-assisted penetration testing on critical public sector applications and shape how government adopts AI-enabled security testing.

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UK Government pilot · 2026 · Names withheld

  1. 01

    Human-led, machine-accelerated

    AI widens recon, varies payloads and speeds triage. Judgement, exploitation and every final call stay with an experienced tester.

  2. 02

    Every finding validated by hand

    No plausible-sounding vulnerabilities. If it is in the report, it was reproduced, risk-rated and comes with a fix your engineers can use.

  3. 03

    Evidence over hype

    Having tested AI pentesting against real public sector applications, I can tell you where it earns its place in your programme, and where it does not.

02Services

Everywhere an attacker would look.

I offer web and API penetration testing, cloud and Kubernetes security assessments, AI-assisted and adversary-led testing, CHECK infrastructure and internal network testing, DevSecOps and secure code review, mobile and wireless testing, and testing leadership including scoping, report QA and mentoring. Each engagement is scoped with you, tested manually and reported for engineers and executives alike, with fixes that survive contact with a real backlog.

  1. Manual-first testing of web applications and APIs. Authentication and authorisation flaws, business logic abuse, injection, SSRF and remote code execution.

    • OWASP
    • APIs
    • Auth bypass
    • SSRF
    • RCE

  2. Assessments across AWS, Azure and GCP, and managed clusters on AKS, EKS and GKE. RBAC, secrets handling, network policies, workload isolation and container hardening.

    • AWS
    • Azure
    • GCP
    • AKS · EKS · GKE
    • RBAC

  3. Pentest delivery that pairs expert testers with AI tooling, independent evaluation of AI security products, and red team thinking where the engagement calls for it.

    • AI-assisted pentesting
    • Tool evaluation
    • Red team concepts

  4. CHECK-scheme infrastructure testing, Windows and Linux build reviews, firewall rulebase reviews and segmentation testing across complex enterprise estates.

    • CHECK
    • Build reviews
    • Firewall reviews
    • Segmentation

  5. SAST, DAST, dependency and IaC scanning wired into CI/CD, threat modelling and secure design reviews, with assurance across the SDLC in line with NCSC guidance.

    • CI/CD
    • SAST · DAST
    • IaC
    • Threat modelling

  6. Android and iOS application testing, wireless audits, RFID cloning and cracking, physical assessments and social engineering including phishing and vishing.

    • Android · iOS
    • Wi-Fi
    • RFID
    • Social engineering

  7. Scoping, intake and work allocation, methodology and reporting standards, QA of other testers' reports, and day-to-day mentoring, while staying hands-on.

    • Scoping
    • Report QA
    • Mentoring
    • Methodology

03Roles

The roles I step into.

From hands-on tester to head of function, I slot in wherever a team needs senior offensive security.

  1. 01Delivery

    Senior Penetration Tester

    Owning complex engagements end to end for government and large enterprise. I validate every finding, judge real-world risk and turn it into remediation advice teams can use straight away.

  2. 02Leadership

    CHECK Team Leader

    Leading large, complex CHECK scheme engagements, supporting other testers on site and remotely, and adapting the plan when the original approach stops being viable.

  3. 03Advisory

    Security Consultant

    Working with clients before and after the test. Scoping to their real risk, shaping bespoke assessment plans, explaining findings to technical and non-technical stakeholders and prioritising what to fix first.

  4. 04Engineering

    Security Engineer

    Embedded alongside engineering and platform teams, improving real controls in production across cloud, Kubernetes, APIs and internal infrastructure, within established risk and compliance frameworks.

  5. 05Strategy

    Head of Product Security

    Setting the product security strategy and building the function behind it. Security in the SDLC and CI/CD, threat modelling, secure design reviews, red team support and coordination of third-party assessments.

  6. 06Leadership

    Testing Lead and Mentor

    Running a testing function day to day. Intake and scoping, allocating work, mentoring testers, quality-assuring reports and keeping methodology and reporting standards consistent.

04Research and craft

What I build and break after hours.

Bug bounty

14,000+

user records exposed by a single authentication bypass

HackerOne profile

Rewarded and publicly acknowledged by major global technology organisations for high-impact findings.

  • 01

    Authentication bypass

    Exposed 14,000+ user records

  • 02

    Remote code execution

    Code execution on the target asset

  • 03

    Server-side request forgery

    Requests turned against internal systems

  • 04

    Cross-site scripting

    Script injection in high-profile assets

  • Hack The Box

    Published training machine

    A multi-tier network inside a single disk image. Players exploit an OpenVPN vulnerability, pivot across segmented networks and beat the firewalls with DNS tunnelling and source port forwarding.

    Released

  • Tooling

    Custom SSRF scanner

    Ingests Burp Suite output, finds injection points in requests and URLs, injects payloads and watches for out-of-band responses.

    Built

  • Hardware

    RFID security

    Hands-on cloning, writing and cracking of low and high frequency cards with the Proxmark.

    Ongoing

  • Dissertation

    Wi-Fi MITM detection

    A 27,000 word study that ran ARP spoofing, DNS spoofing and evil twin attacks, then produced a custom script that detects them in real time.

    94%

05Credentials

Standing, on the record.

Recognised by the UK Cyber Security Council and the NCSC CHECK scheme.

  1. Title01

    Principal (PriCSP), Security Testing

    UK Cyber Security Council

  2. Panel02

    Expert Volunteer Panel member

    UK Cyber Security Council

  3. Pilot03

    UK Government AI security pilot

    Senior tester cohort, 2026

  4. CHECK04

    CSTL (Infrastructure)

    CHECK Team Leader, security testing

  5. Certification05

    OSCP

    Offensive Security Certified Professional

  6. CHECK06

    CHECK Team Leader (CTL)

    NCSC CHECK scheme

  7. CHECK07

    CHECK Team Member (CTM)

    NCSC CHECK scheme

  8. Education08

    First class honours, Computer Networks & Security

    94% dissertation grade

  9. Certification09

    CCNA Routing & Switching

    Passed with 86%, plus a Cisco scholarship for CCNA CyberOps

06Questions

Asked often.

Straight answers about AI-assisted pentesting, scope and working together.

  1. An AI pentester combines human-led penetration testing with AI tooling. AI widens reconnaissance, varies payloads and speeds up triage, while an experienced tester validates every finding by hand, so reports contain reproduced, risk-rated vulnerabilities rather than plausible-sounding guesses. I was selected from across UK Government to help evaluate AI-assisted penetration testing on critical public sector applications.

  2. Web applications and APIs, cloud environments on AWS, Azure and GCP, Kubernetes clusters on AKS, EKS and GKE, internal and external infrastructure, Android and iOS applications, wireless networks, RFID, and physical and social engineering assessments. I also carry out secure code reviews, build and configuration reviews, and firewall rulebase reviews.

  3. Yes. I take penetration testing and security assurance contracts for government and enterprise clients. I am based in Manchester, UK, work remotely by default and travel to site by arrangement. The quickest way to start is to email me with the system, the timeline and your main concerns.

  4. OSCP, CHECK Team Leader, CSTL (Infrastructure) and Principal (PriCSP) status with the UK Cyber Security Council, where I also serve on the Expert Volunteer Panel.

  5. A report written for two audiences. Engineers get technical detail, reproduction steps and practical fixes. Executives get a clear articulation of risk. Every finding is validated, rated for real-world impact and paired with remediation advice your team can act on.

  6. Yes. I integrate SAST, DAST, dependency and infrastructure-as-code scanning into CI/CD pipelines, run threat modelling and secure design reviews, and help teams maintain assurance across the SDLC in line with NCSC guidance.

07Contact

Need a senior tester who knows AI?

Tell me about the system, the timeline and what keeps you up at night. I’ll reply with how I’d test it.

hello@10sec.co.uk
HackerOne
Status
Available for contract
Focus
Web, API, cloud, Kubernetes and AI-assisted testing
Based
Manchester, UK. Remote-first, on-site by arrangement