Penetration Tester & Security Researcher
Ethical Hacker
I break things before the bad guys do. Specializing in offensive security, vulnerability research, and red team operations — helping organizations build resilience through adversarial thinking.
About Me
I'm John Karki, a penetration tester and offensive security specialist with a passion for understanding how systems break — and how to fix them.
My work spans web application pentesting, network security assessments, red team engagements, and social engineering simulations. I operate with a hacker's curiosity and an engineer's discipline.
When I'm not exploiting vulnerabilities for a living, I'm contributing to CTF competitions, researching zero-days, and sharing knowledge with the security community.
Projects
Conducted a full-scope web application penetration test against a fintech platform, identifying critical SQL injection, broken authentication, and IDOR vulnerabilities before production launch.
Led a 3-month adversarial simulation for a mid-size enterprise, achieving domain admin access via phishing + lateral movement, exposing critical gaps in their SOC detection capabilities.
Achieved Pro Hacker rank on HackTheBox by pwning 60+ machines across various difficulty levels, specializing in Active Directory, buffer overflows, and privilege escalation paths.
Discovered and responsibly disclosed a stored XSS vulnerability in a major SaaS platform affecting 500k+ users, resulting in a $4,500 bug bounty reward and a CVE assignment.
Performed a comprehensive internal network penetration test for a healthcare provider, uncovering misconfigured SMB shares and unpatched Eternal Blue vulnerabilities across legacy systems.
Built an open-source reconnaissance automation framework that chains together subdomain enumeration, port scanning, and vulnerability fingerprinting into a single pipeline.
Skills & Certifications
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Contact
Available for penetration testing engagements, red team projects, security consulting, and bug bounty collaboration. Let's build more secure systems together.