Web Application Pentesting
Manual, OWASP-based web app testing covering SQL injection, XSS, authentication bypass, business logic flaws, API security, and more. Every finding includes developer-ready remediation advice.
Currently available for new engagements
Hi, I'm Sandor
Your On-Demand
Penetration Tester
I help SMEs and cybersecurity firms find and fix vulnerabilities before attackers do. With 9+ years of hands-on experience as a freelance and contract penetration tester, I deliver fast, honest, actionable security testing. No generic reports.
Know Me More
Security isn't just my job
it's how I think
I'm Sandor, a Budapest-based freelance penetration tester with a background that spans both sides of software. Before I spent my days breaking into systems, I spent four years building them as a developer which means I understand how vulnerabilities get introduced, not just how to exploit them.
"I don't just hand you a list of CVEs. I tell you what they mean for your business, and exactly how to fix them."
Over the past nine years I've performed web application penetration testing, infrastructure security assessments, network pentesting, and source code reviews for clients in financial services, telecommunications, gambling, and healthcare industries where a breach isn't just costly, it's catastrophic.
Since 2022 I've been working independently under my brand ProCyber, partnering directly with SMEs and with MSPs and cybersecurity firms who need reliable, on-demand pentest capacity they can trust.
When I'm not testing, I'm hiking somewhere off the beaten path which, honestly, isn't that different from what I do at work.
My Journey
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NowProCyberAI/ML Security & PentestingExpanded into AI threat modeling, GenAI prompt injection testing, and secure AI deployment assessments alongside traditional web and infrastructure pentesting.
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NowProCyber · IndependentFreelance Penetration TesterLaunched my independent practice. On-demand pentesting for SMEs and overflow pentest capacity for MSPs and larger cybersecurity firms.
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–Docler Holding, LuxembourgIT Security Specialist
Web & mobile pentesting, infrastructure assessments, source code review, and developer security guidance using BurpSuite and Nessus.
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–KPMG HungaryIT Security Advisor - Pentester
Penetration testing and vulnerability assessments for enterprise clients using OWASP methodology.
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–Invitel, HungaryIT System Developer
4 years of PHP/Yii/Oracle development. The foundation that taught me how software is built and where security gaps are created.
Skills & Expertise
What I bring to the table
Nine years of hands-on offensive security work across the full testing spectrum from web apps to AI systems.
Cybersecurity Disciplines
Web Application Pentesting98%
Infrastructure & Network Security92%
Source Code Review90%
OWASP Methodology & Frameworks97%
AI / GenAI Security Testing75%
Tools & Technical Proficiency
Burp Suite Professional99%
Nessus / Vulnerability Scanners92%
Metasploit & Exploit Development88%
Active Directory & Windows Security85%
PHP / JS / Python (Dev Background)82%
How I Can Help You
Penetration Test Services
Whether you're an SME that needs its first security audit, or a cybersecurity firm under deadline pressure. Here's how I step in as your on-demand penetration tester.
Infrastructure Penetration Testing
External and internal infrastructure security assessments from public-facing servers and cloud environments to network misconfigurations, privilege escalation paths, and Active Directory weaknesses.
Network Security Penetration Testing
Full-scope network tests covering perimeter defenses, segmentation weaknesses, firewall rule analysis, and lateral movement opportunities. I map exactly what an attacker could reach from any foothold.
Secure Source Code Review
I review code the way an attacker reads it, identifying logic errors, missing controls, and dangerous patterns automated scanners miss. With a developer background, my guidance is code-level and immediately actionable.
For MSPs & Cybersecurity Firms
On-Demand Contract Penetration Tester
Need to scale pentest capacity fast without a lengthy hire? I plug in as a trusted senior contract pentester handling overflow projects, specialist engagements, or tight-deadline client work, seamlessly under your brand.
Let's Talk Partnership- Fast onboarding. No lengthy procurement or vetting delays
- White-label friendly. I work under your brand seamlessly
- Senior-level output backed by OSCP, OSCE & CREST CPSA
- Flexible B2B contracts. Project-based, retainer, or hourly
- Reliable delivery even on the tightest client deadlines
- AI/ML and GenAI security testing specialization since 2024
Independent Second Opinion
Penetration Test Review Services
Already have a pentest report in hand? Before you sign it off, or hand it to a client, get an independent, no-conflict-of-interest review that checks whether it truly reflects your risk.
Independent Second Opinion
Penetration Test Review
Not every penetration test reveals every risk. If you already have a report in hand, from an internal team, an MSP, or another vendor, I provide an independent review to validate coverage, catch what was missed, and give you an unbiased read on your real exposure. No conflict of interest, since I didn't write the original report.
Get a Second Opinion- Independent analysis of your existing pentest report and findings
- Complementary attack simulations on critical or high-risk areas
- Evaluation of vulnerabilities in context, not just in isolation
- Neutral, third-party perspective with no stake in the original engagement
- Clear, prioritized, actionable recommendations
For Pentest Teams & Firms
Penetration Test Technical Review Services
Built for pentest teams, departments, and firms that want report review off their testers' plates. Most pentesters would rather be testing than proofreading, whether it's their own write-up or a colleague's.
For Pentest Teams & Firms
Penetration Test Technical Review
Report review is the part of the job most testers would rather skip. I take it on as an external reviewer, having written and assessed hundreds of pentest reports, validating methodology, evidence, and scope before anything reaches your client, so your team stays on engagements instead of on paperwork.
Let's Talk Report Reviews- Technical review of report quality, structure, and write-up
- Evidence and tool output validation. Burp manual + automated, Nessus, and more
- Coverage check confirming nothing was missed, including both TCP and UDP port scanning
- Scope adherence review, confirming full in-scope coverage with no out-of-scope testing
- Actionable feedback your testers can apply before the report ships
Interested in Working With Me?
Ready to find out what an
attacker would see in your systems?
Whether it's a one-off web app pentest, an infrastructure assessment, or ongoing B2B pentest capacity. Let's talk. I respond to all enquiries within one business day.
My Process
How a pentest engagement actually works
Simple, structured, and built around your deadlines. Every engagement follows the same transparent 5-step process.
- Scope
We define targets, rules of engagement, timelines, and goals together. No wasted effort, no scope creep.
- Test
Manual-first penetration testing using OWASP methodology and proven attack techniques. Custom tooling where it matters.
- Report
Clear findings with severity ratings, proof-of-concept exploits, business impact, and practical remediation steps.
- Debrief
I walk your team through every finding in plain language. No jargon, just clarity, context, and next steps.
- Re-test
Once you've fixed the issues, I verify the fixes are solid. We close the loop properly. Not just on paper.
Why Hire Me
Why hire me as your contract pentester
There are a lot of penetration testers out there. Here's what makes me different.
- Developer turned pentester
Four years building software before security means I understand root causes, not just symptoms. My reports speak a language developers actually act on.
- Manual-first, always
Automated scanners miss business logic flaws and chained vulnerabilities. I don't just run tools. I think like an attacker.
- No generic pentest reports
Every finding is tailored to your stack and your real risk. Actionable insight. Not copy-pasted CVE descriptions.
- Flexible, fast, and cost-effective
As a freelance penetration tester, I move faster than agencies and cost less than in-house hires. I adapt to your timeline. Not the other way around.
Industries & Certifications
Financial ServicesCompliance-critical testing
TelecommunicationsLarge-scale infrastructure
Gambling & iGamingBusiness logic testing
HealthcareSensitive data environments
Transport and LogisticsCRM System testing
Postal servicesComplex web app testing
Offensive Security Certified Professional
Offensive Security · 2018
Offensive Security Certified Expert
Offensive Security · 2018
CREST Practitioner Security Analyst
CREST · 2024
FAQ
Common questions about hiring a pentester
Everything you'd want to know before we talk.
When you hire me directly, you know exactly who's testing your systems. A senior, OSCP/OSCE/CREST-certified professional with 9+ years of hands-on experience. No junior analysts, no offshore subcontracting, no account managers as middlemen. Faster turnaround, lower cost, and direct communication throughout. You're buying the person, not the brand.
On-demand pentesting means hiring a certified expert for a specific engagement. No retainers, no long-term contracts required. It's ideal for SMEs needing a one-off assessment, companies preparing for a compliance audit, or MSPs that need to scale testing capacity quickly for a client project without a full-time hire.
Yes. This is one of my core services. I partner with MSPs and larger cybersecurity firms as a white-label contract pentester, handling overflow capacity, specialist engagements, and tight-deadline client work. I integrate into your team and workflow seamlessly, and can deliver under your brand if needed. Project-based or retainer arrangements are both available.
The most respected certifications are OSCP (Offensive Security Certified Professional), OSCE (Offensive Security Certified Expert), and CREST qualifications. OSCP and OSCE are hands-on, lab-based. They prove you can actually exploit systems, not just pass a theory exam. I hold all three: OSCP and OSCE since 2018, and CREST CPSA since 2024.
It depends on scope. A focused web app pentest typically takes 3–5 days of testing. A full infrastructure assessment ranges from 5–10 days. Source code reviews vary by codebase size. I'll give you a precise estimate after our scoping call and I stick to it. Rush engagements are possible when deadlines are tight.
I assess whether the report you are holding actually reflects your risk. That means coverage, was everything in the agreed scope genuinely tested or only the easy parts; validation, is each finding real, reproducible, and rated correctly; and gaps, what a tester with my background would expect to see that simply is not there. I also sanity-check severities against your real environment rather than a generic score, because a high on an isolated internal host is not the same as one on your public checkout page. Where it matters I re-test critical areas myself to confirm. You get a written verdict on how much confidence that report deserves and what is still unknown.
This one is aimed at pentest teams and firms, and it digs into method rather than presentation. I check that the testing behind the report was actually performed: web applications covered with both manual Burp work and automated scanning, Nessus run with its output triaged rather than pasted in raw, both TCP and UDP ports scanned, and authenticated paths tested wherever credentials were provided. Then evidence, does every finding carry proof that supports both the claim and the severity assigned to it. Then scope discipline, everything in scope covered and nothing out of scope touched. Finally the write-up itself, its structure, internal consistency, and whether a client could actually act on it. You get marked-up feedback your testers can apply before it ships.
Get In Touch
Let's talk about
your security
Whether you're an SME that's never had a pentest, or a cybersecurity firm that needs experienced contract pentest capacity. I'd love to hear from you.