Arjen Wiersma


I am Manager Product Development and Chief Lecturer at Hogeschool NOVI. I work on creating the most modern and relevant educational products that we can offer. Through stategic partnerships and attracting the most talented content developers we offer world class education to our students.

In my work as Chief Lecturer for Cybersecurity I focus on teaching students all there is to know about the technical side of Cyber Security. My main areas of expertise are Reverse Engineering, Infrastructure Security and Web Application Security.

Next to my work I am active as an Independent Hacker. I assist my customers in their journey to increase their security posture. I do this through advice, seminars and security assessments. I toot on the fediverse as

I organize the Dutch meetup for Hack The Box. Each month, on the 3rd Wednesday, members of the Dutch cyber security community get together and have presentations, demos and discussion on wide ranging topics. Through this collaboration I have become an Ambassador for Hack The Box.

The views on this site are my own.

Long form articles

Latest writings

Public talks and presentations

From time to time I talk at conferences and meetups.

Hosting a month long CTF
I shared my experiences hosting a month long CTF, the Advent of CTF. The talk can be viewed on YouTube.
Building a Cyber Security Curriculum
I was one of the opening speakers for the Hack The Box University CTF event. In my talk (YouTube link) I explained how Hogeschool NOVI developed its Cyber Security program. I focused on the technical side of the curriculum and how it ties into the Hack The Box platform.
Just enough Reverse Engineering
During the 2nd Hack The Box meetup I talked (YouTube link) about the basics of reverse engineering, the phases of the proces and the tools you can use for it. It was an introductionary talk.

Open Source Projects


Github: link.

A tool to manage your hosts file.


hed allows you to manipulate your hosts file from the command-line. By providing safe and easy commands you can add new hosts and aliases to your environment.

This tool was inspired by my students to whom I teach a Basic Cyber Security class. In this class we utilize Hack The Box as a learning platform and most students struggle with editing the hosts file when they get started. To make this easier for them I wrote a tool that gives them a safe means of adding and removing hosts in this file.

The tool is to be used as a regular user, it will elevate privileges when it requires it by calling sudo and respawning the process.

Pandoc HBO

GitHub: link.

Use markdown or org-mode to write high quality documents for work or school (conventions used by University of Applied Science in The Netherlands).

  • Beautiful PDF documents
  • References and literature listing in APA style

All Projects/Code

  • 09 Oct 2021 Release hed; a tool to manage your hosts file
  • 29 Nov 2020 Released Advent of CTF.
  • 15 Oct 2020 Pandoc HBO release. A setup for Dutch HBO/Master students to write beautiful reports.
  • 15 Oct 2020 Docker Pandoc release. A docker image that contains pandoc and all necessary packages for report generation based on the eisvogel LaTeX template.

Write Ups

Advent of CTF 2020

December 2020 I hosted the Advent of CTF. 24 days long a new challenge was posted every day. There were more the 500 registered users and over 400 active players! You can find all the writeups here.

Fun references

  • I was referenced in a talk by Martin Clausen. He gave a presentation on a Clojure build and in the conclusion he talked about knowing your tools. Thanks for the hat-tip!