Concept
Obfuscation through Hashing (Algorithm Recognition): Using hashing functions to generate dynamic file paths based on environment variables (whoami).
Key Commands
md5sum: Generates an MD5 hash of the input.cut: Filters text columns based on delimiters.
Walkthrough
I analyzed the /usr/bin/cronjob_bandit23.sh script and discovered that the password for bandit23 was being copied to a file in /tmp/ whose name was the result of an MD5 hash of the phrase “I am user bandit23”. I manually replicated the hash generation command in the terminal to obtain the filename and read it using cat.
Key Takeaways
I learned that security through obscurity (hiding something under a strange name) is useless if the attacker knows the algorithm generating that name. I also practiced using pipes to chain Bash logic.
Command Breakdown
echo I am user bandit23: Simply prints the string. Note: This is the “seed” of the hash; any mistake in spaces or casing changes the result completely.| md5sum: MD5 (Message Digest Algorithm 5) generates a 128-bit “digital fingerprint” (32 hex characters). While no longer secure for real passwords due to collisions, it’s a classic for obfuscating filenames in Bandit.| cut -d ' ' -f 1:-d ' 'sets the delimiter to a space.-f 1selects the first field, cleaning the hash and leaving only the 32 characters.
Pass 23
0Zf11ioIjMVN551jX3CmStKLYqjk54Ga