Another nice CTF. This one was pretty laid back went for over a weeks time. Seemed to have a lot of Stego and crypto challenges pretty low on an type of reverse or forensics. Everything seems to have gone smoothly I didn’t notice any issues. Some members of OverflowSecurity were in and out of the challenges. Here are the write ups for the ones that I completed.
Put on your reading glasses (10 pts)
run strings on file. flag is on the bottom
What you see is what you get. (50 pts)
run strings the bottom shows us the program used and key to extract
steghide –extract -sf stego_50.jpg
wrote extracted data to “key_stego_1”.
key_stego_1 stegcrack.pl stego_50.jpg
root@kali:~/CTF/pragyan/stego/what-you-see-is-what-you-get# cat key_stego_1
Congrats! This was way too wasy 😛
This is the key:
One more headache (20 pts)
This is a PRGYAN event
text file called substitution given with the following text
assuming that PRGYAN is the key
used an online decoder
entered key: prgyanpr cipher text: dhkuagsn
Access Code (30pts)
Find the access code
a PDF is shown
RIP JPEG from PDF ( can right click and save it)
this is the JPEG
Did a google image search via drag and drop image into search box and find the artist name is Sascha Herm
The PDF said KEYED painter so go to online keyword cipher decoder
use KEY: saschahermsasch
with Cipher Text: heitsctrnpsmysk
and get the flag: deltactfpragyan
Totally abstruse (30 pts)
no point guessing
was given an image.
A goggle image search on this images brought up the Piet programming language.
found an online interpreter at
execute the image/code
Welcome to npiet online !
Info: upload status: Ok
Info: found picture width=115 height=115 and codel size=5
Uploaded picture (shown with a small border): world.png
Info: executing: npiet -e 1000000 world.png
Flag: Hello, world!