Facebook games are fun .... to hack!


This is about how I learnt about logos with the help of a facebook game named The Logo Game. During vacation because of extreme boredom in holidays, I finally started to look for some time consuming stuff :P. Eventually I stumbled upon Facebook games in particular a game called The Logo Game.

Logo Game

The game was really cool (at the beginning). But the awkward thing that I noticed is that, if a correct guess was provided it was taking time to respond & for a wrong guess the reaction was instantaneous. So, it is reasonable to open tamper data and check for the data submits. For a correct solution there was a request being done and for wrong as expected no request was taking place. So I started diving into the source code :). What caught my attention was ==>

MD5 Salt

md5_salt :o , so I could guess what was going in the backend. So it was easy for me to search the remaining js code for relavent part & I found this

Guess Function

So I went for logos.CheckGuess

Check Function

Yay!!! We got it, so some hashes were being passed to app, and checking is done in our browser itself (The app was combining the answer with a salt and then hashing it and checking the hash against the existing values ) . So now we have salt and hashes. Are we going to crack it????? NO WAY. When I tried to replicate the application's way of communicating with the server through ajax, I got the some data in json format. I tried fuzzing the input parameters and I could get the whole data of logos and hashes ( also those which I don't have access as my score is not so good ). So the data after a bit of injections appeared like this =>

Fuzzing result

I just underlined few of the data because almost all the data is important. We have hints, md5 hashes and names of the logos. So I wrote a python script to extract logo names from this trash and the output of my program appeared like =>

Check Function

Just a snapshot of a part of the output file. So now I have all the logo names in order. The file is available for download here. Finally there are loads of ways to learn stuff. So I started learning about logos this way.

P.S - The score that I have in the game is legible and is not obtained through any unfair means :P

Anyone can download the logos list and verify. Incase of mistakes please let me know as I have to correct my script then :P. Trust me all this was fun rather than the normal game.


2013-03-26 :: {bugs}