│ Category: Reverse Engineering
│ Author: Imattas aka Zemi
│ Flag: byuctf{why_do3s_yara_st4nd_f0r_th4t???}
│ Source Path: rev/yara
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--[ Challenge Description ]--
-- text --
# Yet Another Recursive Acronym
Maybe use `--no-warnings` for quality of life.
Note: there should not be an unintended, but if you find one let the admins know
Files:
- [rule.yar](https://github.com/BYU-CSA/BYUCTF-2026/blob/main/rev/yara/rule.yar)
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--[ Provided Materials ]--
- Repository folder https://github.com/BYU-CSA/BYUCTF-2026/tree/main/rev/yara
- rev/yara/README.md
https://github.com/BYU-CSA/BYUCTF-2026/blob/main/rev/yara/README.md
- rev/yara/rule.yar
https://github.com/BYU-CSA/BYUCTF-2026/blob/main/rev/yara/rule.yar
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--[ Recon / Initial Analysis ]--
This page imports the BYUCTF 2026 source material for the Reverse Engineering
challenge Yet Another Recursive Algorithm. The prompt is kept separate from the
solve notes, and upstream artifacts are linked so the challenge can be replayed
from the original repository.
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--[ Vulnerability / Observation ]--
The useful observation comes from the imported solve notes below. I kept the
original technical path intact while normalizing the page metadata, challenge
grouping, and author attribution for the Volume 2 writeup archive.
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--[ Exploitation / Solution ]--
Source: rev/yara/README.md
https://github.com/BYU-CSA/BYUCTF-2026/blob/main/rev/yara/README.md
This is a yara rule that does matching on a file to check whether or not the
flag is contained within it. Many people did this manually to solve it, but it
could also be done with a sat solver if you want to be fancy, just make all the
conditions be met. Goal here is just to introduce you to yara and all the fun
stuff that comes with it.
Flag: byuctf{why_do3s_yara_st4nd_f0r_th4t???}
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--[ Full Exploit Script ]--
No standalone exploit script was present in the selected source material.
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--[ Key Takeaways ]--
- The BYUCTF 2026 challenge material is preserved with local archive formatting.
- The page author is normalized to Imattas aka Zemi.
- The source repository remains linked for handouts, services, and solve
artifacts.