How are self-extracting executables made? - executable

There are many programs out there that will allow you to pack a few files together and generate an executable that has the necessary code to extract them. Somehow, those files are residing inside the executable. I am interested in doing the same thing; how is this done?
FYI, I'm interested primarily in Windows .exe files, if it makes a difference.

Look at this: Article

You could probably save a file/files in a resource, compile it into the exe then use some code in the exe to extract it out to a file.
ie:
http://www.codeproject.com/KB/winsdk/binaryresources.aspx

Self extracting .exe files are usually archive files (zip, rar, tar, etc) concatenated together with a small program that does the extraction then executes the program that was extracted from the archive.
A really sophisticated one could extract the archive into memory and then jump to the extracted code and run it, but back in the old days, that sort of thing was easier to do.
If you wanted to write your own in Windows, you would create a small console application that did the extraction, and you would include the 'real' program in the console programs' resources.

There are also products like pkzip and winzip which do it for you. If your time is worth anything, those would be more efficient.

UPX is a well known packer for Windows .EXE which can be found here on WikiPedia. And here is the main site on sourceforge for UPX.
Hope this helps,
Best regards,
Tom.

Related

How can I protect my VB.NET App.exe from decompressing?

I made a small program (App.exe) by (Visual Basic Language) that replaces some files, and a place those files in my preject recoures
the problem is when i build the program i can decompressing the App.exe and see those files like a archive with any decompressing software like a WinRAR or 7-zip, and me i don't want that, this is a image from my computer, someone can help me, thanks in advance
You may use ConfuserEx obfuscator (Google it to get that). After encrypting the app with it, it'll be almost impossible to decompile it or get its raw files (resources) even after extraction.
Simply drag and drop your application into it:
Use Compressing packer:
And finally protect it:
And you're good to go.

Burn .exe 'output format' is 'opaque'?

Disclaimer: I'm fairly new to burn...
The .exe files created by WiX Burn bundles are some type of self extracting zip archives, however they seem fairly opaque in structure and I cant find any documentation on them. For example in 7zip a Burn .exe looks like this:
Whereas a traditional .vdproj bundle (and other bootstrappers I have seen) include the bundled files verbatum in a traditional file system.
QUESTIONS:
Is the output format documented anywhere?
Is there any way to
recover the contents without installing? EDIT it seems dark.exe can do this, so 2a. is there anything outside the WiX toolkit...
Is there any way to
change the output format?
Thank you.
NB The reason I ask is that there are many circumstances (corporate IT departments say) where people extract the .msi files out of traditional bootstrappers to wrap into their own logic / examine the bootstrapper contents as part of an approval process.
No, the format for an attached container is undocumented (intentionally, so we can change it later). Today, in WiX v3.10, it's a .cab file attached to the .exe.
(a) It's possible but there are no such tools today (that I know of) other than Dark.exe.
No, not today. Obviously, you could use external payloads so they're not attached to the .exe.

Macromedia Director: Decompile EXECUTABLE File

It is possible to extract executable files??
If it is what are the possible software may i use?
it depends how deep you want to dig into the executable and what kind of data you need from the exe.
As with all exe files you can analyse them on a low level. But I assume you want to have a high-level tool to get back the director files that were used to create the exe, right?
For the exe-file (the "projector" to use the appropriate director wording) there is no such tool known to me.
But very often the exe file is used together with files with extensions such as .dxr or .dir. Those are director files. DXR-Files are protected. But by importing them into director you can extract some of the cast memebers (graphics etc.) that are included. You need in-deep knowledge of lingo to do so.
You might also find .cst or .cxt files. Those are cast files. They can hold media, scripts etc. too. CXT are the protected versions. For these files the same is true as for the DXR and DIR files.
All in all - it is not easy and your chances are low to completly reveal all code and media. Most director programmer use the protected files for distributing their programs. Those do not allow to reveal all data included.
This Python script extracts Macromedia / Adobe Director movies and casts
from Windows and Mac executables.
https://github.com/n0samu/director-files-extract

Implement a self extracting archive?

I know i can use 7z or winrar but i want to learn this for myself.
How would i implement a self extracting archive? I can use C# or C++ but let me run down the problem.
When i open the exe i need some kind of GUI asking where to extract the files. Once the user says ok I should obviously extract them. I implemented a simple example in C# winforms already BUT my problem is HOW do i get the filenames and binary of the files into an exe?
One upon a time i ask Is it safe to add extra data to end of exe? and the answer suggested if i just add data to the end of the exe it may be picked up by a virus scanner. Now its pretty easy to write the length of the archive as the last 4bytes and just append the data to my generic exe and i do believe my process can read my own exe so this could work. But it feels hacky and i rather not have people accuse me of writing virus just because i am using this technique. Whats the proper way to implement this?
Note: I checked the self-extracting tag and many of the question is how to manipulate self extracting and not how to implement. Except this one which is asking something else Self-extracting self-checking executable
-edit- I made two self extracting with 7z and compared them. It looks like... well it IS the 7z.sfx file but with a regular 7z archive appended. So... there is nothing wrong with doing this? Is there a better way? I'm targeting windows and can use the C# compiler to help but i don't know how much extra work or how difficult it may be programmatically and maybe adding data to end of exe isnt bad?
It is possible. I used the following technique once, when we needed to distribute updates for the application, but the computers were configured so that the end user had no permissions to change application files. The update was supposed to log on to administrator account and update required files (so we came across identical problem: how to distribute many files as a single executable).
The solution were file resources in C#. All you need to do is:
Create a resource file in your C# project (file ending with .resx).
Add new resource of type "file". You can easily add existing files as byte[] resources.
In program you can simply extract resource as file:
System.IO.FileStream file = new System.IO.FileStream("C:\\PathToFile",
System.IO.FileMode.OpenOrCreate);
System.IO.BinaryWriter writer = new System.IO.BinaryWriter(file);
writer.Write(UpdateApplication.Data.DataValue, 0, UpdateApplication.Data.DataValue.Length);
(Here UpdateApplication.Data denotes binary resource).
Our solution lacked compression, but I believe this is easily achieved with libraries such as C#ZipLib.
I hope this solution is virus-scanner-safe, as this method creates complete, valid executable file.

CGZIPLibrary.dll not compressing files

HI, I am using CGZipLibrary.dll in my code for zipping the files. A .zip file is being created but the file is not getting compressed. The original file and the .zip file are of same size.
Please provide some suggestions. Thanks in advance.
CGZipLibrary.dll... that's a rather old library if my memory is serving me right, I remember using it (or some other library with a similary name) in some old VB6 projects, and I had to update it because it had some problems when compressing folder structures. I may have the updated library lying somewhere around.
For .Net there are better alternatives like SharpZipLib and DotNetZip. I see the question is tagged with VB6 as well... if you need to use the library from VB6, from what I know, DotNetZip is marked as visible for COM, so you should be able to use it as well, although haven't tried it myself.