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PicoCTF Lookey Here Writeup: Finding a Flag with grep

A short picoCTF Lookey Here walkthrough using grep to search a large text file for the flag pattern.

Apr 10, 20242 min readAdapted from my picoCTF notes
PicoCTFForensicsgrep

Lookey Here is a picoCTF 2022 forensics challenge about searching through a large text file. The flag is hidden in plain text, but the file is too large to inspect manually.

Since picoCTF flags follow a predictable prefix, grep is enough:

grep "pico" anthem.flag.txt

Flag

grep output

Key Takeaways

  1. Pattern matching is often the fastest solution for large text artifacts.
  2. Know the expected flag format and search for it directly.
  3. Prefer grep over manually scrolling through noisy files.