General Remarks
CTF Page Link: https://umdctf.io/
UMDCTF had a large array of challenges that tested different aspects of offensive security but I was mostly drawn towards OSINT challenges.
Mirror Unknown [Forensics]
Challenge Context
I found some unknown symbols in a nearby collapsed cave. Can you figure out what they mean?
(Note: Ancient civilizations didn't believe in whitespace or lowercase)
Solution
The challenge description came with the above image attached.
After doing a Google Image Search I learnt that it was Pokemon Alphabet called 'Unown' and each symbol represented a regular alphabetic letter.
I found two possible ways to decipher this:
The first method above was my first attempt, I used https://www.dcode.fr/pokemon-unown-alphabet.
This attempt was unsuccessful - I had noticed that from the image I got some symbols were inverted (did not tally with the provided symbols on the platform).
That's when I got a hint from the title of the challenge 'Mirror Unkown' - I assumed that this image was somehow inverted (rotated).
With the help of https://www.img2go.com/rotate-image, I was able to rotate the image both on the x and y axis and deciphering the image was easy - I just tallied the symbols to the Unown Alphabet to get the flag.
I, of course, had to append
UMDCTF{}to the flag for it to be accepted.
Gone Missing 1 [OSINT]
Challenge Context
A fire type Pokemon has gone missing. Can you find it?
Solution
The challenge descriptions for Gone Missing 1, 2 and 3 had a link to the above website.
This OSINT (Opensource Intelligence) challenge gave us a 360 google street view picture of a random location and to 'capture the flag' or solve the challenge a player was supposed to give the precise location where the picture was taken.
For Gone Missing 1, the picture below was provided:
My trick on this challenge (both 1 and 2) was to zoom in on a significant landmark or object on the image, take a screenshot and do a reverse search with Google Images 'search by image' feature on the browser.
For this challenge, I zoomed in on the horse statue and the building behind it and did an image search.
- From the search, the image identified the location as the 'Royal Palace' (or det kongelige slott in Norwegian) in Norway, Oslo.
- I looked at the location of this place on my full-screen google maps so that I could match it with the map provided on the challenge website.
My first attempt was the location of the actual palace, but this was incorrect.
The location required was the precise location from which the image was taken, in this case, the palace square.
Gone Missing 2 [OSINT]
Challenge Context
A grass type Pokemon has gone missing. Can you find it?
Solution
- For Gone Missing 1, the picture below was provided:
- Using the same concept as challenge 1, I did a reverse image search while zooming in on the star (it was the closest significant landmark).
- This search did not give a precise location so I had to go through multiple articles to learn that the location of the star on the image was Castle Rock, Colorado, USA.
- After further research to find the precise location of the star within the town, I discovered its location in Rock Park.
- After several attempts, I managed to find the precise location - it was relatively difficult because you had to guess the correct angle from which the image was taken.
TCC1
Challenge Context
I found this hacker group and they're acting kinda strange. Let's do some diggin'. Maybe we can find their discord server? I thought they linked it on their website before...
Solution
- The challenge description had a link to a website for the mentioned 'hacker' group attached.
After looking around on the website I couldn't find the mentioned discord link.
This is when I decided to use the Way Back Machine ( https://archive.org/web/ ) which essentially stores older versions of a website.
- After discovering an earlier snapshot of the website I opened it and found the discord channel link attached.
