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(a clever, beautiful protection: wars between keys and the FFFFFFF8 monster) by Hackmore Readrite , 7 January 1998 |
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( )Beginner (x)Intermediate (x)Advanced ( )Expert
An useful essay for intermediate and advanced crackers in order to see an example of some of the paths followed by clever protectionists when developing new protection schemes. Read and head: not all of them are stupid. |
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How To Crack A Ferret (a clever, beautiful protection: wars between keys and the FFFFFFF8 monster) Written by Hackmore Readrite |
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No intro |
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~ Target URL |
Usual tools Softice is a must ~ Targets Size Description ------- ---- ----------- EFT111.EXE 690 Kb E-mail Ferret FFT111.EXE 724 Kb File Ferret IFT111.EXE 678 Kb IRC Ferret NFT111.EXE 694 Kb News Ferret PFT111.EXE 673 Kb Phone Ferret WEBFERRET110.EXE 620 Kb Web Ferret WFPEV.EXE 732 Kb Web Ferret Pro Evaluation Copy FROM: ftp://ferret.aitcom.net/pub/ferret AND: http://www.ferretsoft.com/ferret/ |
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No history |
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H E E S S A Y |
Notes: Program descriptions are available at the "http" address, but
the "Web Ferret Pro" program is ONLY available at the "ftp" site. Also
available at the "ftp" site is a program named "NFupgrade111.exe", which
is just an upgrade utility to convert "older" versions of these programs
to the "current" version, which is Version 1.11 for all of the programs
listed except the Web Ferrets.
WFPEV.exe is time crippled at install AND at run-time. It is also
"missing" some code to turn off the advertising, but I'll show you how
to get around these problems later. Despite these "problems", you'll want
to download "WFPEV.exe" instead of "WebFerret110.exe" because "WFPEV.exe"
is the "PRO" version, which does boolean searches, allows deletes, and
has several other "nessesary" features. Get it as soon as you can,
because it has already expired and will probably be removed from the
server as soon as someone notices it's still taking up space.
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WHAT DO THESE PROGRAMS DO?
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These are very compact "search engines" which live on your hard drive.
You enter query strings, just like you would at any search engine, and
these programs will search ALL of the search engines you select. The
results can be saved for future use, or used imediately if you choose.
For instance, using Web Ferret and Win95 as an example, you would go
to "find" on your "start" menu, click "web pages" to start the program,
type in "fravia" and "cracking" as the items to search for, then click
"find", and you'll get a listing containing every web page listed on the
search engines that contain the text "fravia" and "cracking". Point your
mouse at any listing, and you'll see the begining text from that web page,
click on a listing to open your browser and load the web page.
The boolean feature in the Pro version is especialy helpful. You can
search for "cars AND trucks [but] NOT convertibles", as stated by the
company. Features like these can be real handy when searching for a
certain file, web-site, E-mail address, or IRC channel.
------------------------------------------------------------------------
WHAT'S THE PROBLEM?
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Cash flow, or boredom, depending on WHY you crack. These programs are
VERY reasonably priced, and worth the investment! It was the sales
tactics which drew my attention to these programs, and the encryption
technique which drew my interest.
When you install these programs, you enter your name and company, then
click the "next" button, and enter your serial number and registration
"key", or just leave these two feilds blank to take the program for a
test drive.
After installation, you'll want to run the program, of course. It is
then that you will discover the sales tactics. A banner will continualy
display adds, on YOUR monitor! This can NOT be tolerated! The "view"
menu has an "option" to turn OFF advertising, but this option has been
disabled, until you register the program.
They could have lost a sale because the time I WOULD have spent earning
money to pay for these programs HAD to be spent removing thier advertising
instead. How do they expect me to test drive thier product with those
awful banners constantly distracting me?
Even though we've got the program installed on our hard drives, the
original install program is nessesary to register the program, so don't
delete it yet. Let's fix these programs so we can test them without all
of those distractions! The Web Ferret Pro is totaly different from all
of the other programs listed above, so I'll cover it a bit later in this
essay, but here is what you'll need to fix ALL of the other programs.
------------------------------------------------------------------------
Even though we will NOT be going into the encryption scheme used in
this program in this essay, I urge you to study it. It wont be nessesary
for cracking these programs, but the author has done a very fine job of
encrypting things, and deserves honors for his style and technique.
Unfortunately, he forgot that, no matter how well he encrypts his
passwords, it MUST always boil down to a simple "go here, or go there"
instruction in the end.
For those of you who are too lazy to study, I'll give you a short
description of how this encryption scheme is implimented. For those of
you who DO study this, be VERY careful, one slight miscalculation will
crash your computer! You should become very familiar with the "hboot"
command inside Soft-Ice. Even minimizing the loader screen to the
taskbar will lock up your computer.
The serial number must contain five digits for reasons I'll explain
later, and the "key" number must contain nine digits to activate the
"next" button, which is deactivated as soon as you enter the first
digit of the serial number.
After you've typed in your serial number and registration key number,
locate them, and set BPR's on them inside Soft-Ice. Then click on the
"next" button. You'll break into the protection scheme at CS:004026D4.
The "key" that you typed in, as you'll learn, is the "key" to unlocking
the program. The serial number is only used to set a counter.
The "key" value does it's usual trip through memory addresses until
it finaly ends up on the stack. The center digit has been removed, so
now your "key" is a "handy" eight characters long, so it fits nicely
into the registers. After the string was shortened to eight characters,
it was counted in the usual mannor by placing FFFFFFFF in ECX. The result
was inverted, as usual, to obtain the "decimal" byte count of "8", but it
was also saved, uninverted as FFFFFFF8, to crash your computer!
At this point, we find another key already waiting for us at DS:0041C540.
This second key is 12h bytes long, and is comprised in three parts,
using the starting values:
"12345678" "23456789" and "34567890"
To make a long story short, these three groups of eight numbers are
sent to war against the "key" value you typed in, AND against the other
"eight number" groups. It's like a war between four countrys, with EACH
country fighting the other three countrys. They are beat against each
other in just about every way imaginable until nothing is left but a
mangled, un-recognizable, eight character string of garbage.
From time to time, the 12h byte string is "refreshed" with the
original numbers I've listed above. But the war continues. And when the
smoke has cleared, we can finaly do a few comparisons. If you've followed
this through, you should find yourself at CS:0040EC3D.
Again, the author was very clever. Every time you THINK EAX should be
set to "01", it should be a "00", and vise versa. Keep this in mind,
because, as I mentioned earlier, we're set up to crash! Any time you
choose the "wrong" path to take after a CMP or TEST instruction, the
program will find its way back to that FFFFFFF8 monster, and use it to
crash your system. So choose wisely. Remember that you've entered bad
data, so if the program "wants" to go one way, it probably "should" go
the other way instead. Also remember, thats NOT always true!
But, alas, we've made it to the check point. Lamers can just set your
breakpoints to the following addresses. Lamers are lamers because they
miss all of the fun stuff, YOU decide who you are!
------------------------------------------------------------------------
1st check: ; [ESP+0C] holds the
; encrypted value of
; your input "key"
:0040EC3D 8B44242C mov eax, dword ptr [esp+2C] ; the GOOD number
:0040EC41 83C40C add esp, 0000000C
:0040EC44 3944240C cmp dword ptr [esp+0C], eax ; the first "test"
:0040EC48 7525 jne 0040EC6F ; a bad place to go!
------------------------------------------------------------------------
Here, the GOOD value is stored at [ESP+2C]. Then it's MOVed to EAX to
be CoMPared to the encrypted value of the "key" you typed in, which is
stored at [ESP+0C]. Assuming EAX is "59 42 55 f8" and [ESP+0C] is
"22 47 39 23", you might encounter a slight "problem" when you arrive at
the JNE instruction. To repair this "problem" when the two numbers do NOT
match, simply edit memory in Soft-Ice, as follows:
d esp+0c
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These programs are the ONLY programs sold by FerretSoft. If you make a
key generator, or crack these programs and give them away for free to lamers
in ANY form, you will be damaging FerretSoft in a way which COULD put them
out of business and you will still remain a lame idiot anyway, since anybody
on the scene will know that you just ripped my essay off!
Please STUDY these protection schemes, and use them all you like in
order to implement and ameliorate your own protections, but if you
decide to KEEP the ferret programs, please PAY for them. The programmer(s)
(must be at least two: a clever one that devised the protection and an
idiot that devised the advertising cram) have worked very hard to create
these beautiful protections for us, they studied encryption techniques the
same way you have, and worked very hard to implement those techniques in
an effective manner. They did a great job, but messed up just a bit at
the end.
This is NOT a "greedy" company like M$, they have priced thier products
very reasonably. Even thier advertising techniques are "original" to say
the least. So be kind, and treat this company with a bit of respect. If
you do, they might dream up even BETTER stuff for our private pleasure.
Search well...
Hackmore Readrite
Data Miners Inc.
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I wont even bother explaining you that you should BUY this target program if you intend to use it for a longer period than the allowed one. Should you want to STEAL this software instead, you don't need to crack its protection scheme at all: you'll find it on most Warez sites, complete and already regged, farewell. |
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