S.H.E.L.L. CTF - Challenges
Contents
SHELL CTF Forensic Challenges
1. Cold Compress
Not much going on in this one. Download the image file you’re given and run binwalk against it to extract the embedded executable. I pulled the file up in Ghidra to see that all it does is print out the flag.
2. Grass Is Green
This one is simple as well. Open the image in an editing program such as GIMP and raise the brightness until you can see the flag.
3. Hidden Inside 1, 2 and 3
I forgot to screen shot the challenge info for all the Hidden challenges but they’re all basically the same. The file is just modified for each challenge.
For Hidden 1 change the extension to .png to view the file. You can just run zsteg against it to find the flag.
Hidden 2 is also a png file with the wrong extension. You can run zteg again but this time it finds a hidden png file within the image.
|
|
Hidden 3 is an a jpeg file which we can utilize JPEG Hide and Seek on to extract the hidden file. There was a hint on the challenge that gave the year a program was created which made finding the JPHS program easier to find.
