Offensive Security & Security Tooling

Security built on
real-world expertise

Grepsi Security provides penetration testing, threat modelling, and open-source security tooling — helping teams find and fix vulnerabilities before attackers do.

OWASP aligned STRIDE & LINDDUN Free open-source tooling No data collection

What we offer

Practical security work delivered by practitioners — from structured tooling to hands-on offensive engagements.

Live

Threat Modelling Tool

Browser-based STRIDE and LINDDUN threat modelling — 8-step OWASP-aligned workflow, interactive DFD, risk matrix, PDF export. Free and open-source, with no data ever leaving your browser.

Launch tool →
Coming soon

Penetration Testing

Web application, API, and infrastructure penetration testing delivered against OWASP WSTG and PTES methodologies. Detailed, actionable reporting for development teams and executives.

Register interest →
Coming soon

Security Research

Published vulnerability research, CVE disclosures, and open-source tooling. Built in public — follow along as we ship.

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Security by practitioners, for practitioners

Offensive mindset

We think like attackers. Every engagement is driven by real threat intelligence, not checklists.

Open by default

Our tooling is open-source, our methodology is documented, and our findings are yours to keep.

Standards-aligned

OWASP WSTG, PTES, NIST, and STRIDE/LINDDUN — rigorous methodology, every time.

Developer-friendly

Reports that development teams can actually act on — not 200-page documents with no clear next steps.

Ready to improve your security posture?

Start with our free threat modelling tool, or get in touch to discuss a penetration testing engagement.