Some Assembly Required 1 (Medium)

  • Challenge Link: https://play.picoctf.org/practice/challenge/152?category=1&difficulty=2&page=3
  • Challenge Description: N/A
  • Hints:
    1. Try inspecting the WebAssembly module output and the loading script.

Solution

Assembly (assembly language) is a low-level programming language that talks almost directly to the computer’s CPU. It is just one step above machine code (the 1s and 0s). It uses short instructions like: mov (move data), add, jmp (jump).

In the image below, you can see the fetch function which is used to get data from a URL. Then the webassmebly loads and runs the data.

If you use the inspect element, you can find the flag buried in the files. 

picoCTF{68ff4bc93f6d67637b2f471be209d132}

Sources

  • N/A