Deloitte Hackazon Writeup Phase-3 | sh4d0wless

PHASE 3 QUESTIONS

Happy New Maldoc (Reversing) 125 point

As seen in challenge name it is about document with malware. I opened this slide on my windows machine. (I tried something on ubuntu libre office but something went wrong.)
This document contains only one slide and button on that. I opened the macro section (view -> macro) and start enumerating the vba script code. This code contains lots of trash functions and at the bottom of them ı found the funtion that run when we click the button.

This function have 2 variable, one of them is cap and another one is sHN. cap get the values from left function and sHN gets the value from enviroment variable.
We can add variables and functions calls to “Add watch” section with right click -> add watch. I added some variebles and set breakpoint(f9) on if block.
In if block it checks the sHN and if its correct, it prints success message and the sHN is our pc name :D As seen on watches section is checks is our pc name is “SANTA-PC” or not. You can change your pc name to “SANTA-PC” or change the sHN befora the if check.

I replaced sHN with the requested value and run teh code and flag appeared on the watches section :) Flag is :

CTF{im_a_maldoc_pro}