First Find | picoGym Exclusive Solutions

Description

Find uber-secret.txt hidden somewhere inside the provided archive. Hidden directories (those prefixed with a dot) might conceal the answer.

Setup

Download the archive and extract it. Grep can inspect the expanding tree faster than manual browsing.

Hidden directories (prefixed with .) appear once the archive is unzipped, so make sure your shell shows them.

wget https://artifacts.picoctf.net/c/500/files.zip

unzip files.zip && rm files.zip

Step 1Locate the hidden folder
Once unzipped, the structure includes .secret nested multiple levels deep. Rather than traversing each directory by hand, let grep reveal which file mentions picoCTF.
grep -R pico
Step 2Inspect uber-secret.txt
Grep output shows that files/adequate_books/more_books/.secret/deeper_secrets/deepest_secrets/uber-secret.txt contains the flag. Read it directly to confirm.
cat files/adequate_books/more_books/.secret/deeper_secrets/deepest_secrets/uber-secret.txt
Step 3Trim the output
If you only want the flag text, pipe grep through an extractor such as grep -oE, cut, or sed to strip away the path prefix.
grep -R pico | grep -oE 'picoCTF\{.*\}' --color=none

picoCTF{f1nd_15_f457_ab44...}

Once you know the hidden directory path, viewing uber-secret.txt prints the precise flag shown by grep.