Capture the Flag

by: Matthew O'Neil

This will be a place for me to store CTF writeups/solutions to interesting problems I find while participating in CTFs. Some of these will be easier and some harder. I have been doing CTFs for some years know and figured I'd document my progression.

What are CTFs?

For those who are not familiar with CTF, Capture the Flag, competitions, allow me to introduce you.

Jeopardy style capture the flag competitions or challenges are basically jeopardy for Cybersecurity. The players are given problems relating to a category such as reverse engineering or cryptography and have to come up with a solution to find 'the flag'. The flag is a string of characters which normally follows the same format across CTFs of ctfname{th3_F4k3_f14G}.

Red-team/blue-team CTFs are competitions where there are two rounds where each of two teams take turns pen-testing the blue teams environment with the intent of finding the flags. This type is the lesser played of the two but nonetheless are also fun to participate in with a good team.

Where are these CTFs?

The number one place I go to find competitions is CTFTime. There are also well known capture the flag competitions hosted by PicoCTF and Hack the Box.