There was a CTF challenge on campus, and for extra credit my instructors said we could attempt some of the challenges.
Stenography - Scout out the flag
I noticed a bar on the bottom and right edges of the picture, so I knew there was something hidden in the pixels. I googled some online stenography tools, and after playing around for a while I ended up finding this: https://incoherency.co.uk/image-steganography/#unhide. Putting the picture into the software yielded the results below:
Crypto - Transportation Cipher
In this puzzle, I was given a flight itinerary and a list of nights, given here. After playing arounf with the nights nad tying to find a relationship between teh locations, I was recommended by an instructor to look up the flight codes for each location, so for eaxample Baltimore might become BWI. After this it was just a matter of translating each location to it's airport codes, for which I used this site. I was able to decrypt the message to be
FLA -> GIS
MAR -> YLA
NDR -> ULE
SAT -> CTF
which reads across as 'Flag is Maryland rules at CTF'.
Then all I had to do was figure out how the flag was formatted. I soon got echo -n "UMDCTF-{marylandrulesatctf}" | sha256sum to output the same sha256sum as the one on the challenge page. Puzzle complete!
Reverse Engineering - Baby's First RE
Next up was this challenge. I opened up the ELF file in radare2, saw a funky-looking baby made in ascii art, and a weird long string VU1EQ1RGLXsxX1NlZV9QcjMzdHlfU3RyaW5nel9ldmVyeXdoZXJlXzFfZ299. I wasn't really sure what to do with it, so I looked around the rest of the code, but it seemed like that was the clue. On a whim I decided to try and see if it was encoded in Base64 (like one of the easter eggs in class we had one time), and sure enough it was! I was rewarded with this flag -> UMDCTF-{1_See_Pr33ty_Stringz_everywhere_1_go}. Woot woot!