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Dig for dummies

Explaining an highly useful network tool

May 24, 2019
Learn how to use the dig command to query domain name servers to find the source of network problems, IP-addresses, hostnames, mail servers and related info.

When you're building websites, apps or email services you may run into domain names and their configurations. When everything is working as it should, most of this is invisible. But when troubleshooting a domain name configuration, it may be necessary to dig a little deeper... read along to learn how!

WordPress: 10 tips to secure your website

Keep hackers out of the world's most popular content management system

Mar. 31, 2019
A lot of people use WordPress to manage their website. Prevent your site from being hacked using this blog post.

A lot of people use WordPress to manage their website, therefore it's no surprise people ask me to have a look at their site's security. As ethical hacker, I encounter WordPress in different shapes, sizes and states. Some of them are really badly protected against hacks. Prevent your site from being hacked using these 10 practical tips.

Understanding the security concerns in shared hosting

Considering open ports and unused network facing services

Feb. 28, 2019
People pay me to hack them, provided I'll explain how I did it. Read along to learn how hackers use security holes to hack your app, webshop or website!

People pay me to hack them, provided I'll explain how it was done, so future hacks can be prevented. As security consultant, I scan for weaknesses in my clients' apps, webshops and websites. Very often a hack starts by exploiting a security hole that is visible remotely. Read along to learn how hackers find security holes and what you can do to secure them.

Is the Apple Watch the modern tool watch?

Testing the Apple Watch's usefulness in real life

Nov. 2, 2018
I tested the Apple Watch during my work in Frankfurt this week where I had to go inside an internet data centre.

This week I went to Frankfurt for business. I had to perform maintenance to servers in a data centre. This seemed like a great opportunity to test the Apple Watch's usefulness in real life (other than health and fitness). I wondered, is the Apple Watch the modern tool watch?

Optimising images for the web and performance

Reduce filesize with jpegoptim, optipng, pngcrush and pngquant

Sep. 26, 2018
Make your website faster by optimising the images. This posts explains how you can do this.

One way to make your website faster is to make it smaller. Not with tiny fonts, but with less bytes! More than half the weight of an average website is because of images. Yet very few people optimise their images for the web and performance, time to find out how much bytes you can safe!

Google Analytics vs AWStats

Understanding web traffic statistics software

Aug. 20, 2018
Comparing Google Analytics with AWStats to find out where they differ and which is better.

This month I have been working on website statistics, tracking traffic using different technologies. Some of my customers use Google Analytics, others use AWStats, and some use both. Which is better is often debated, but few people really understand the differences. Time to shed some light on the magic of web statistics.

Cyber security: 5 easy tips to protect your server against hackers

Server hardening best practices for Windows and Linux

Mar. 10, 2018
These 5 practical cyber security measures will improve the safety of server, website and data.

This week one of my clients was hacked and asked me for emergency assistance to help secure their server infrastructure. It was a web server that ran WordPress websites on Apache (with PHP/MySQL), including a few webshops with customer data. This hack could easily have been prevented with the following best practices, is your server secure?

Updating Snake '97

About the challenges of developing a wildly popular game

Feb. 21, 2018
This month I bit the bullet big time: I redesigned the game engine of the wildly popular Snake '97 game. Read about the design challenges in this blog post.

Few years ago my brother threw a beer on my iPhone in an Amsterdam bar. The poor thing didn't like the Dutch brew as much as I do: it died. While waiting for a new phone to arrive, I used an old one that couldn't do anything but texting, calling and... Snake! The idea for Snake '97 was born and this month it was time to update the wildly popular game.

Clouds below my floor

Building a little datacenter in my basement

Aug. 31, 2017
Building a little datacenter in my basement utilising a very fast internet connection.

At my home I have this crazy fast optical internet connection. It is a 600MB up and down fibre connection which directly arrives in my home (no copper cables involved). It's like a private internet highway. Reason enough to find out if I could do something to make better use of all this speedy fiber galore...

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Robots surfing the web: bot traffic listed by AWStats
Robots surfing the web: bot traffic listed by AWStats
Check the reputation of a WordPress plugin by looking at the number of downloads and its rating
Check the reputation of a WordPress plugin by looking at the number of downloads and its rating
The world on your wrist - using Apple Maps in downtown Frankfurt
The world on your wrist - using Apple Maps in downtown Frankfurt
Leaking personal user information from the WordPress REST API
Leaking personal user information from the WordPress REST API
Bitmap images are like chessboards, where the pixels are squares
Bitmap images are like chessboards, where the pixels are squares
Inspecting quality: left original, right pngquant
Inspecting quality: left original, right pngquant
Analysing gameplay speed differences using slow motion video
Analysing gameplay speed differences using slow motion video
German warning signs inside the data centre (somehow they feel slightly more serious...)
German warning signs inside the data centre (somehow they feel slightly more serious...)
Snake '97 running on iPhone X - looking and feeling like the retro mobile phone game from the 90s
Snake '97 running on iPhone X - looking and feeling like the retro mobile phone game from the 90s
Using dig to get information about the SPF-records for a domain name, google.com
Using dig to get information about the SPF-records for a domain name, google.com
Limit access by IP basis to XML-RPC using a .htaccess file
Limit access by IP basis to XML-RPC using a .htaccess file
Password dictionary attacks use lists of known (leaked) passwords, you can find them on shady parts of the internet
Password dictionary attacks use lists of known (leaked) passwords, you can find them on shady parts of the internet
Data Centre in Frankfurt
Data Centre in Frankfurt
Though a hatch near my front door I have access to the space below the floor.
Though a hatch near my front door I have access to the space below the floor.
Typical piece of Google Analtyics JavaScript code - you can clearly see it referring to Google's servers
Typical piece of Google Analtyics JavaScript code - you can clearly see it referring to Google's servers
Café 't Pakhuis in Amsterdam - where Snake '97 was
Café 't Pakhuis in Amsterdam - where Snake '97 was "invented"
Sniff WordPress password using WireShark packet capturing (via blog.wpscans.com)
Sniff WordPress password using WireShark packet capturing (via blog.wpscans.com)
The actual code from Snake '97 handling distance calculation using the Pythagoras Theorem
The actual code from Snake '97 handling distance calculation using the Pythagoras Theorem

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