Modifying Binary Save Game Data (iPhone)

admin

Administrator
Staff member
Just for fun, I'm trying to hack my saved game data for the Ghostbusters iPhone app (<a href="https://itunes.apple.com/us/app/ghostbusters/id583354857?mt=8&amp;uo=4" rel="nofollow">AppStore link</a>).

The following sites describe replacing
Code:
Documents/save.dat
with the pre-hacked version:

<ul>
<li><a href="http://www.iapphacks.com/ios-free-hacks-f3/ghostbusters-v1-0-1-t8597.html" rel="nofollow">http://www.iapphacks.com/ios-free-hacks-f3/ghostbusters-v1-0-1-t8597.html</a></li>
<li><a href="http://mobilegamingsquad.wordpress.com/2013/01/24/ghostbusters-hack/" rel="nofollow">http://mobilegamingsquad.wordpress.com/2013/01/24/ghostbusters-hack/</a></li>
</ul>

However, I want to modify the data myself. Using a hex-editor on my
Code:
save.dat
revealed the following dead-ends:

<ol>
<li>I could not find the value for the amount of money in any combination of the following: (little endian, big endian), (unsigned, signed), (integer, float), (4, 6, 8, 16 byte value), (1 through 15 byte offsets)</li>
<li>Any small change (ie: item purchase) seems to completely rewrite and change the data file.</li>
<li>A quick scan of the file in ASCII reveals no text clues to the format of the file. <em>ADD:</em> In fact, all ASCII strings within the file seem completely random.</li>
<li>The linux command
Code:
file
simply identified the file as
Code:
data
. </li>
<li><em>NEW</em> Compressing the file enlarges it, so the file is likely compressed or encrypted.</li>
<li><em>NEW</em> I'm neither jailbroken nor an iOS developer, so I do not have access to the app's internal memory.</li>
</ol>

How might this file be encoded? Any suggestions on how I might modify it manually?