top of page

CONCIERGE APPROACH, PROVEN SUCCESS

Safeguarding organizations at every scale, from emerging ventures to global leaders.

In chess, castling is both a defensive move that protects the king and an offensive maneuver that brings the rook into play to strike. It's a perfect metaphor for our mission: Defend your critical assets while positioning your team to proactively stand against emerging threats. Through red teaming, penetration testing, and security reviews grounded in attacker methodology, we help defenders stay ahead of the next move.  

​

Since 2017, Castling has delivered impactful results protecting organizations against critical security threats. Our service has prevented over $50 million in fraud losses, uncovered verification bypasses that exposed more than 3 million identity records, demonstrated a full compromise of a corporate network by bypassing multi-factor authentication, and identified remote code execution vulnerabilities on internet-facing systems for some of the world’s largest technology companies.

​

Castling has also exposed sensitive data leaks and critical business logic flaws at major e-commerce and streaming platforms, serious issues that could have allowed attackers to steal revenue through unauthorized discounts and entitlements. Most recently, Castling experts discovered and pioneered the security approach of a new class of application security vulnerability—Recursive Request Exploits—which was noted at DEFCON 2025 for its far-reaching impact on API and business logic security.

Castling, Castling Security, penetration testing services, red team operations, offensive security services, attack surface management, application security testing, cloud security assessment, vulnerability assessment services, security consulting firm, cybersecurity assessment services

FOUNDED BY

FARZAN KARIMI

Castling, Castling Security, penetration testing services, red team operations, offensive security services, attack surface management, application security testing, cloud security assessment, vulnerability assessment services, security consulting firm, cybersecurity assessment services
Castling, Castling Security, penetration testing services, red team operations, offensive security services, attack surface management, application security testing, cloud security assessment, vulnerability assessment services, security consulting firm, cybersecurity assessment services
Castling, Castling Security, penetration testing services, red team operations, offensive security services, attack surface management, application security testing, cloud security assessment, vulnerability assessment services, security consulting firm, cybersecurity assessment services

Speaker, Leader, & Cybersecurity Pioneer

FARZAN KARIMI

Farzan Karimi is a seasoned Red Team leader and security expert who has shaped offensive security programs at some of the world’s most influential organizations, including Google, Microsoft, Electronic Arts, and Moderna. Over the course of his career, he has led teams in uncovering critical vulnerabilities, developing advanced adversary simulation capabilities, and driving security strategy at a global scale.

​

A four-time Black Hat and DEFCON speaker, Farzan’s pioneering work has earned recognition across the security community, with features in WIRED magazine and on Ted Danson’s Advancements. His contributions span research, innovation, and mentorship, reflecting a commitment to elevating the industry’s standards for resilience and defense.

Protect what matters.
Strike where it counts.

Contact us to learn more about how we can future-proof your security infrastructure.

bottom of page