Skip to content
View chvancooten's full-sized avatar
πŸ•΅οΈ
Probably hacking
πŸ•΅οΈ
Probably hacking

Organizations

@Offensys

Block or report chvancooten

Block user

Prevent this user from interacting with your repositories and sending you notifications. Learn more about blocking users.

You must be logged in to block users.

Maximum 250 characters. Please don't include any personal information such as legal names or email addresses. Markdown supported. This note will be visible to only you.
Report abuse

Contact GitHub support about this user’s behavior. Learn more about reporting abuse.

Report abuse
chvancooten/README.md

Hey πŸ‘‹, I'm Cas

Red Teamer β€’ Offensive Tool Developer β€’ Co-Founder of Offensys

Building offensive security tools in Go β€’ Python β€’ Rust β€’ Nim

Website Twitter Sponsor


About Me

I'm a Red Teamer based in the Netherlands who likes to play around with anything related to hacking, security, programming languages, or tech in general. I love to learn, but I love sharing the things I've learned even more. In my free time, I build offensive security tooling in modern programming languages like Go, Python, Rust, and Nim.

I publish my projects publicly as open-source software in a responsible manner (a much-debated point, I know). The premise is simple: transparency strengthens security. When we build tools in the open, both attackers and defenders can level up their game.

As a co-founder of Offensys, I'm working to make continuous purple teaming accessible to organizations that want to proactively validate their security posture through automated adversary simulation.

Always happy to chat about offensive security, red teaming, or the latest programming languages! Feel free to reach out via Twitter or email.


🎯 Featured Projects

🎯 NimPlant

Lightweight C2 implant written in Nim and Rust
⭐ 929 stars | 🍴 115 forks

A first-stage C2 framework showcasing what modern languages can do for operational security.

Practical malware development workshop
⭐ 1,744 stars | 🍴 206 forks

Hands-on workshop teaching malware development fundamentals. Used by security professionals worldwide.

Code snippets for Offensive Security's PEN-300
⭐ 1,388 stars | 🍴 475 forks

Notable code snippets from my OSEP journey. Community favorite for exam prep.

Automated reconnaissance for bug bounty hunting
⭐ 916 stars | 🍴 127 forks

Bash script and Docker image for headless bug bounty reconnaissance.


πŸ’» Tech Stack

Go Python Rust Nim C#

I specialize in building offensive security tools, red teaming infrastructure, and C2 frameworks using modern programming languages.


πŸ“Š GitHub Stats


🎀 Speaking & Conferences

I regularly share knowledge through conference talks and workshops. Check out my conferences repository for slides, materials, and recordings from past presentations.

Recent talks include malware development workshops, red team operations deep-dives, and sessions on building offensive security tools in modern languages. If you're interested in having me speak at your event, feel free to reach out!


πŸ’Ό Offensys: Continuous Purple Teaming

As co-founder of Offensys, I'm building a platform for continuous purple teaming. The idea is simple: continuously validate your security controls against real-world attack techniques through automated adversary simulation.

Instead of point-in-time assessments, Offensys provides ongoing security validation that's driven by threat intelligence and executed safely in your environment. We're making purple teaming accessible to organizations that want to proactively test their defenses.

Interested in learning more? Check out offensys.nl or reach out for a demo.


πŸ“« Get in Touch

For security professionals: Questions about offensive development, red teaming, or security topics? I'm always up for a chat. Reach out on Twitter or via email.

For organizations: Interested in continuous purple teaming? Visit offensys.nl.

For contributors: Many of my repos welcome contributions. Check out open issues or propose new features!


Website Twitter Offensys

If my content or open-source contributions have helped you, consider sponsoring me on GitHub β˜•

Stay geeky πŸ€“

Pinned Loading

  1. NimPlant NimPlant Public

    A light-weight first-stage C2 implant written in Nim (and Rust).

    Rust 932 118

  2. NimPackt-v1 NimPackt-v1 Public

    Nim-based assembly packer and shellcode loader for opsec & profit

    Nim 488 78

  3. maldev-for-dummies maldev-for-dummies Public

    A workshop about Malware Development

    Nim 1.7k 211

  4. BugBountyScanner BugBountyScanner Public

    A Bash script and Docker image for Bug Bounty reconnaissance. Intended for headless use.

    Shell 917 127

  5. OSEP-Code-Snippets OSEP-Code-Snippets Public

    A repository with my notable code snippets for Offensive Security's PEN-300 (OSEP) course.

    C# 1.4k 475

  6. follina.py follina.py Public

    POC to replicate the full 'Follina' Office RCE vulnerability for testing purposes

    Smarty 1.1k 255