The challenge is based on analyzing a .iso file in order to get the flag. I highly recommend using Autopsy or FTK Imager for challanges like this.
Upon opening the ISO using 7-Zip, we notice a folder named [SYS], which contains a file called Journal.txt. Viewing this file in Kali Linux, we discover a string that appears to be a key — possibly meant for decryption or decoding later on.
all files (opened with 7zip)
encryption key
Next, after searching and went in a lot of useless file, I discovered in bin directoy that we have a binary string at the end of unusually_long_ls file, which could be helpful.
binary string
Analyzing the Data
Up to this point, we now have two critical pieces of information:
A binary string
A key (likely ASCII)
After inspecting both carefully, I tried to XOR the binary string with that key and get the final flag.
