Michael Grafnetter
Principal Security Researcher at SpecterOps
Prague, Prague, Czechia
Summary
🤩
Rockstar🎓
Top SchoolMichael Grafnetter is a Principal Security Researcher with 11+ years focused on Active Directory, Microsoft Entra ID and PowerShell-based security tooling. He invented the Shadow Credentials attack, has disclosed multiple Azure AD weaknesses (earning a Microsoft bug bounty), and regularly speaks at top security conferences including Black Hat Europe and SecTor. As author of the widely used DSInternals PowerShell module and other open-source tools, his work is foundational to many Active Directory auditors and penetration testers. Michael combines deep offensive security experience—running high-success simulated phishing campaigns and enterprise AD assessments—with hands-on development of encryption and credential-handling features. Based in Prague, he blends academic training in software engineering and ongoing PhD research with practical consulting and training, making complex identity attacks both reproducible and defensible.
11 years of coding experience
11 years of employment as a software developer
Ph.D. (unfinished), Software systems, Ph.D. (unfinished), Software systems at Charles University (Univerzita Karlova)
English, German, Czech, Slovak, Hungarian, Russian
Stackoverflow
107reputation
36kreached
4answers
1question
Github Skills (21)
it-security10
audit10
security10
active-directory10
code-auditing10
audit-logging10
cryptography10
dotnet-core10
powershell10
csharp10
auditing10
audit-trail10
data-structures8
data-structure8
error-handling7
Programming languages (14)
Github contributions (5)
MichaelGrafnetter/DSInternals
Dec 2015 - Dec 2022
Directory Services Internals (DSInternals) PowerShell Module and Framework
Role in this project:
Back-end & Security Engineer
Back-end & Security EngineerContributions:46 releases, 348 commits, 41 PRs in 7 years
Contributions summary:Michael's commits focus on the development of the DSInternals PowerShell Module and Framework, which is described as a tool for Directory Services Internals (DSInternals) and security auditing. Their primary contributions involve the creation and modification of source code, specifically focusing on handling and presenting NT status values and preparing the module for new releases. The user also worked on encryption-related functionalities like parsing PEK lists and password hash generation, suggesting a focus on security aspects of the project.
powershell-modulesdataminingntdspowershellpenetration-testing
MichaelGrafnetter/MichaelGrafnetter.github.io
Mar 2019 - Mar 2025
New Blog POC
Contributions:2 PRs, 243 pushes, 5 branches in 6 years 1 month
jekyllpoc
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.