Thursday, August 25, 2016

FLARE On 2015 - Challenge 3


About:


This is the 3rd challenge from FireEye's 2015 "FLARE On" challenge (http://flare-on.com/)


Solution:

This one looks a little different from the first two.

This time we're given a single executable file that, given the icon, looks like it may be derived from a python file using something like py2exe:



Let's see what happens when we run it.... Looks like a picture pops up like this:



So it's not immediately clear what this gets us, but let's go ahead and see if there's a way to recover the original source code if it was indeed made from Python code.


I decided to use pyinstallerextractor, which confirmed it was derived from some Python2.7 code:



Now let's take a look through the extracted code....

The file that immediately stuck out was "elfie", which looks like more obfuscated Python code:




Thousands and thousands of lines.... until finally:




Ok, let's see if we change the "exec()" call to a print() and dump the results to a new file:



Looks pretty good.... wait what's this?


Woo hoo!

Elfie.L0000ves.YOOOO@flare-on.com









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