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Welcome!

I’m Koen . I live in Bruges (Belgium), a splendid medieval city also known as the Venice of the North.

I’m involved with computer security and I work as a freelancer in incident response, incident coordination, threat intelligence, vulnerability management and security best practices. Basically all tasks related to managing a CSIRT / CERT (Computer Emergency Response Team).

My main interests in computers are security, web applications (PHP, MySQL, Apache), system administration and free software.

This site hosts a blog and I have a photo collection at Flickr.

Latest posts

ENISA Threat Landscape 2022

I contributed to the ENISA Threat Landscape 2022. The ETL is an annual report on the status of the cybersecurity threat landscape. It identifies the top threats, major trends observed with respect to threats, threat actors and attack techniques, as well as impact and motivation analysis. It also describes relevant mitigation measures.

Get a copy of the ENISA Threat Landscape 2022.

CTI-Summit 2022 Luxembourg Presentations

The first edition of the Cyber Threat Intelligence Summit took place in Luxembourg in October 2022. I did two presentations:

One presentation on MISP web scraper, a tool to create MISP events and reports from scraped websites; and one presentation on building CTI Operational Procedures with Jupyter Notebooks and PyMISP.

The slides and recording are available on GitHub and Youtube.

Slides: https://github.com/cudeso/misp-tip-of-the-week/tree/main/CTIS-2022; Recording of CTI Operational Procedures with Jupyter Notebooks and PyMISP; Recording of MISPRead more.

Down the Chainsaw path to analyse Windows Event logs

Chainsaw is a tool to rapidly search through large sets of Windows Event logs. In this post I briefly go through the steps that I take to collect, process and analyse logs from different Windows machines and then use them for analysing Windows Event logs. Obviously it’s always better to use centralised logging and apply your detection techniques centrally but unfortunately this isn’t always possible.

Although Chainsaw is available as a binary packageRead more.

MISP web scraper

I published an article on the MISP project website on the MISP web scraper.

There are a lot of websites that regularly publish reports on new threats, campaigns or actors with useful indicators, references and context information. Unfortunately only a few publish information in an easily accessible and structured format, such as a MISP-feed. As a result, we often find ourself manually scraping these sites, and then copy-pasting this information in new MISP events. TheseRead more.

Analysing Amazon AWS security groups and access control lists

Analysing firewall rules in AWS can be complex. There are Security Groups (SG) as well as Access Control Lists (ACL). Security groups are applied on instances and are the first layer of defense, whereas access control lists are applied on network components (subnets) and are a second layer of defense. A major difference is that SGs are stateful, whereas ACLs are stateless. From a filtering perspective there is also a difference. In security groups allRead more.

Cyberweapons Arms Race

I recently finished the book “This Is How They Tell Me the World Ends: The Cyberweapons Arms Race” by Nicole Perlroth. The book covers the story of the cyberweapons market and how government agencies fuelled this economy, eventually making the Internet a less safer place for us all.

I added some notes of items of interest in a mindmap that are maybe of use for others. The map is not complete at all, feel freeRead more.

MISP sharing groups demonstration video

Sharing groups in MISP are a more granular way to create re-usable distribution lists for events/attributes that allow users to include organisations from their own instance (local organisations) as well as organisations from directly, or indirectly connected instances (external organisations).

For a possible future project I had to document if sharing groups are an answer for a sort of multi-tenancy for sharing threat events within MISP.

Sharing groups certainly provide an answer, as long asRead more.

MISP and Microsoft Sentinel

A short post with things to consider when integrating MISP threat intelligence with Microsoft Sentinel. There are two documentation resources that describe the integration in detail and should get you started in no-time:

External Connectors for MISP Integrating open source threat feeds with MISP and Sentinel

This error is caused by invalid client secret or missing client ID. One of the steps in the documentation involves creating a new secret. You then have to addRead more.