Problem with extra-data area relocated after compression [topic changed by mod]

Started by sparkies, June 14, 2010, 11:11:47 AM

Previous topic - Next topic



I intend to buy the sdk to add some licensing code (I did post a few eeks ago). Anyways, prior to buying the sdk I need to make sure I can actually compress my app... but it won't work.. I have tried a lot of settings to no avail, the application starts but then .. nothing.

Anybody here who might be able to advise? Note that I am not too bothered about the compression part, obfusciation would already be good and I need to be able to have a custom dll (hence the SDK)...

The app is an e-learning program which has extra-data appended to it....

When I use for example the "messagebox" codec the messagebox appears but then the program complains about JPEG errors, I suspect it is at that point trying to extract the data and finds garbage...




Hi, could you post your compression settings from the log window?

Jeremy Collake

Your assumption is probably correct. The extra-data area will have changed phyical offsets after compression, causing the e-learning code to not be able to properly access it on disk.

If this is the case, I can fix this condition through an API hook plug-in. It is a common problem seen by SFX and installers where extra-data is appended at the end of the PE physical image.

If you can guarantee me the purchase of the Loader SDK, I can guarantee you I will make this work (or your money back). You will need to give me some development time, but it will not take long. Are you the one I've spoken to via email, trying to authenticate your company with my new 'anti-malware' screening?
Software Engineer. Bitsum LLC.

Jeremy Collake

As a result of this I finally finished long-standing plans (and a partial implementation) of Overlay Emulation. So far as I know, PECompact is the first packer to offer this feature. As of v3.03.7, PECompact will now correctly compress self-extracting archives, installers, and other 'constructed' EXEs like those of some interpreted languages. Further, as usual, I provide options on how you want the overlay to be included. You can choose to have it as part of the PE image, and therefore passed through the CODEC(s), or keep it outside the PE image, so it can loaded on-demand from disk. When the host executable attempts to read from itself, PECompact will redirect the read to the correct location on disk (or in virtual memory if you chose to include the overlay in the PE image).
Software Engineer. Bitsum LLC.