Hypothetical situation ;) ...Say one's got two versions of a program...one is a demo with certain features disabled and the other is a lite version with the relevant working features...how would one go about transplanting the working features from the lite version into the demo version? Any pointers in the right direction would come in handy... hypothetically of course :D GeO
Posted on 2001-02-20 09:15:00 by GeO
irc: efnet: #cracking4newbies. http://tsehp.cjb.net
Posted on 2001-02-20 09:38:00 by f0dder
It depends on how a feature has been "disabled" as you put it. If the code simply does not exist, this is much more of a problem, if it has merely been disabled, then there is scope for re-enabling! Some schemes are so lame they rely on greying out menu items! Others are more complex, each needs to be evaluated on its own merits. However as this is a programming forum, I'd suggest your question should be "How can I make it difficult to hack my program". But if you do that, beware those who think open source is God! Mirno
Posted on 2001-02-20 09:53:00 by Mirno
Always take out the code, a certain company released a demo a few years ago, and it was 'time limited' someone took out the limit and ta-da! the whole game was available.... umbongo
Posted on 2001-02-20 10:58:00 by umbongo
You'll need a good knowledge of the PE file format (see, e.g., Iczelion's PE tutorials) and have to patch the relocations to accommodate the extra space taken up by the inserted code. First, use a disassembler (such as IDA) to identify the code of interest and then incorporate it into the exe. The best discussion I've seen of how to do this is in "The Giant Black Book of Computer Viruses" by Mark Ludwig. See especially the chapter on the Yeltsin virus; the technique employed there can be used to "automate" the patching so you don't have to do it all by hand (this would be a nightmare). Of course, you'd defang the virus. I believe Guilfanov is offering a freeware version of his IDA disassembler -- an earlier version to be sure, but still quite useful. See his website http://www.datarescue.com/ida.htm. The full latest version is $300. By the way, I'm NOT a virus writer and don't think viruses have much of a future in the short-to-midrange time frame -- but Ludwig's book describes techniques that every low-level programmer should know about. His book is also a great way to learn more about the PE file format in practice. (It's TASM oriented.)
Posted on 2001-02-20 13:20:00 by Xmas
Not only Icz tuts, but his tools are very useful once you have the knowledge. You can add sections of code, or imports, or exports. They make this kind of thing so easy...I mean easier than the difficulty is obviously is :P bitRAKE
Posted on 2001-02-20 18:31:00 by bitRAKE