“picoCTF” writeup series

A “Capture the Flag” (or CTF) approach can be applied to anything, from real world games to computer games to self-teaching. Having a specific, limited goal to work towards can really focus the mind and is less overwhelming than trying to achieve a more ambitious goal in one improbable leap. In this series, I take a look at one of my favourite CTF exercises out there, known as “picoCTF”. Each flag must be entered in the format “picoCTF{some letters and numbers here}”. I started with Forensics, one of the most interesting infosec fields.

Setting up a Linux machine

First things first. In order to complete many of these CTF challenges, you will need to have a machine with a Linux distribution installed as your operating system.

Not to worry if you don’t have another physical machine to spare: there are several options available to you:

1. Enable dual booting on your computer so that it is bootable either with Linux or whatever other operating system you are using
2. Install software that allows for virtualisation, i.e. the running of virtual machines on your physical machine (note: you may also need to change your BIOS settings in order to enable virtualisation). I used WMWare Workstation Pro, but there are other options out there such as Oracle VM VirtualBox.

Next, install a Linux distribution. I installed xUbuntu 16, but it doesn’t really matter for our purposes.

Now, let us continue to the first writeup.