Questions tagged [decompilation]

Process of translating assembly code extracted from a binary file in a structured programming language, such as C.

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Is this file compressed, and if yes what type of compression is it. And how can I find it myself

I'm once again stuck on a binary image, which seems like it might be compressed, but I can't find any way to detect the compression used, let alone decompress it. The binary in question is from a "...
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93 views

IDA subroutine code running when not being called

Im trying to find where this subroutine is being called in IDA. I use xrefs to see where the subroutine is being called and I NOP the all the calls in all the subroutines in the xrefs. I do this for ...
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74 views

How to find where a subroutine is being called (ida)

I am reversing an application using IDA. I have found a small subroutine that returns information at the end of that subroutine. However I would like to see the subroutine that uses this small ...
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841 views

Exporting/Importing all function info from one ghidra program to another

I'm looking for a way to export all infos about a function (Call signature including custom storage, local symbols, etc) in a ghidra program and import them into another ghidra program, but at a ...
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Seeking for explanation about “ in_FS_OFFSET ” and “ __stack_chk_fail() ”

This is the part of the picoCTF 2019 problem "Investigative Reversing 0". I've encountered the following code when using Ghidra: if (lVar1 != *(long *)(in_FS_OFFSET + 0x28)) { /*...
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How to decompile obfuscated Python code?

I have an executable file, which I am trying to decompile. I have already deduced that it was originally programmed in Python. I know that it was obfuscated with PyArmor and possibly compiled with ...
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109 views

JEB Decompiler - Signature recognition engine

I've been playing around with the JEB decompiler and Android reverse engineering suite. One interesting feature they have is deobfuscation by library code matching in which 3rd party libraries out ...
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619 views

How can I debug a non-main .NET assembly using dnSpy?

I am performing a security assessment on a .NET application. dnSpy is a great tool to do this. However, I've reached a module which is not in the "main" section of the program... It is loaded by the ...
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107 views

Can relative offsets in instructions like call and jmp change after recompiling the same code, or running it in another computer?

So let's say we want to use some instructions as signature for a malware, and it includes some call instructions or jmp instructions. Now, as far as I have seen, they always contain relative offsets ...
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How to reverse engineer an exe built using nexe?

I am working on an express application. I obfuscate the source code using javascript-obfuscator. I am using nexe cli for generating a single exe from the obfuscated code. Can anyone tell me if there ...
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Type reconstruction ambiguity

In TIE: Principled Reverse Engineering of Types in Binary Programs, Lee J. et al claim to solve most of the challenges in the process of C code decompilation that come with type reconstruction. While ...
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735 views

IDA - How to resolve "Write access to const memory detected" error?

I'm trying to analyze a binary that I unpacked, rebuilt, and dumped, using Scylla. After loading it into IDA and viewing pseudocode, I can see that there are errors where IDA tells me that it notices ...
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How do I read this decompiled code?

I want to know what command line arguments are accepted by an application. I have decompiled it using Ghidra and found a function called ParseCommandLine, but I don't understand what it is doing. I ...
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VC 6 C++ Exception handling, nTryBlocks=0, pTryBlockMap=0 , how?why?

I'm trying to decompile an old binary (about 20 year old). The program uses exceptions. I found some FuncInfo but they do not contain any pTryBlockMap and nTryBlocks is 0. I've tried many options ...
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1answer
397 views

Stack-pointer analysis failed

I'm testing my toy obfuscating C compiler against IDA's decompiler, but IDA refuses always functions (then the decompilation is not possible). For example, at one of lowest-levels of obfuscating, a ...
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Ghidra analyzing hardcoded indirect jumps

I'm currently analyzing a function that has a lot of indirect jumps looking like the following. LEA R10,[0x142000000] (some instructions that dont change R10) JMP R10 The Ghidra decompiler just ...
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1answer
105 views

Type inference inconsistency

I'm testing several decompilers against the following C code static int bar(int i) { return ++i; } static int apply(int (*fun)(int), int i) { return i % fun(i); } static int foo(int (*app)(...
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1answer
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IDA pseudocode support

How can I know which processors IDA knows how to view pseudocode of? If IDA does not know to view pseudocode for my processor, how can I fix that??
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Best way to protect source code of .exe program running on Python?

I am developing proprietary software that would be distributed in a form of .exe file. In order to use it, users will have to authenticate with their whitelist credentials (username + password). The ...
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561 views

Struct reconstruction in decompilers

I'm testing several decompilers about struct reconstruction, given the following C example: struct S { int x; int y; long z; long t; }; int foo(struct S s) { return s.x + s.y + s....
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reverse engineering obfuscated .net dll

I am decompiling a third party .NET dll which was obfuscated using codeveil my aim is to get full source code, I tried decompiling using dnSpy, JustDecompile & Reflector however it just shows the ...
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Finding PEM passphrase that may be in an executable?

I'm trying to capture the TLSv1.2 traffic of an application. In the applications directory is the file cacert.pem that I assume holds the cert for decrypting the TLS traffic. I tried to load it into ...
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Deconstructing Unity games

Note: I only want to edit/mod the games not trying to steal things etc. I'm trying to deconstruct some Unity games from both PC and Android platforms and already extracted assets with uTinyRipper ...
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275 views

Can I decompile a file if I have a compiler? [closed]

Is it possible to reverse the compiled code using a compiler? I have a compiler in the form of exe and using it I can compile the file. But there is no possible instruction I got to decompile a file. ...
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1answer
986 views

Why is fastcall used for replacing thiscall functions in memory instead of cdecl?

Assume I were to be reversing some game which processes all of it's movement client side and have determined some function to be of the type: bool __thiscall Player::CanJump(Player *this) that I ...
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257 views

How to decrypt a file who encryption and key is unknown? [closed]

Here is the file that I am trying to findout a way to decrypt. settings.ini This file is from the settings of the MetaTrader 5. The same is the name of the application. Kindly suggest a better way so ...
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How do I reverse engineer a game using dnSpy?

I've been reading some about reverse engineering and decided to try to learn as I go, which has proven somewhat difficult. Sorry about the generic title, I'll try and give enough info so it can be ...
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1answer
312 views

Decompiler attack

I noticed that Hex-Ray have been keeping reward to people who find "security vulnerabilities" of IDA-Pro.: So here is my question, how come a decompiler can have "security vulnerabilities"? And more ...
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concat22 in ghidra decompiler

Some portion of code I am analyzing gets decompiled as below in ghidra: if (((*puVar8 == CONCAT22(DAT_0040a37a,DAT_0040a378)) && (*(uint *)((int)puVar9 + 6) == (CONCAT22(...
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226 views

What is, and why, "byte[ ] + number" in this IDA pseudocode?

This is a decompile of an .so file, so it originated from C or C++. Can you kindly try to explain to me what this does? How would one rewrite this into readable code? I don't mind any programming ...
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How can one replace bitmap (image) inside exe?

I have an application (something like a text editor) that has a background image. I understand how to replace text in exe file, but what about image? I wonder how difficult and what is the way to ...
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2answers
1k views

How to help IDA to auto complete libc functions?

I have a x86_64 ELF binary which is statically compiled. With some digging, I have found the C library is musl. In IDA Pro 7.0, the decompiled pseudo code shows sycalls as inline assembly code. But in ...
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804 views

Java reverse engineering tool [closed]

I'm getting started on Java reverse engineering but I can't find a great tool. I'm currently using JD-Gui to decompile it. I've tried PNF's JEB which is really perfect but it's only for Android stuff....
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How to add symbols from open source lib to Ghidra?

I have a binary which I can tell is using rapidjson (open source C++ library) (header only/not dynamically linked). How can I load debug symbols from that? It would help to see the types, function ...
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137 views

How Can I Clean Up After IDA Decompation with IDAPython or other resource

When I am working on a source code recovery project I am usually left with a lot of code that needs to be manually cleaned up by hand. This can take a lot of time and as projects get larger , I am ...
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134 views

Strings weirdly split in binary

Recently I have come across a few parts in a binary that looked odd to me, and I wanted to ask if this is something common compilers do, and if there is a way to undo it. (The binary is from a raw ...
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How to find implementation of native method in the library .so (Android)

I need to make reverse engineering of one android app. In this app I found class with name Im2MessageNative, this class contains a lot of native methods. For example: static native long ...
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(Help) APK Decomplied unreadable .pngs

I decompiled an Android game APK to look at the source code / resources and the .pngs give me the error "It looks like we don't support this file format" when I try to view them in the Photos App. I'...
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The executable file makes a unique ID from each individual PC. Can anyone decipher from where the file makes these unique IDs?

The file generates random unique ID. It says hardware ID but I couldn't find it in product key, BIOS serial number or anywhere. I used IDA but I couldn't get from where the file creates the code. Even ...
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1answer
382 views

Confusion about LEA and why it means what it does in this context

I am reading Eldad Eilam's reverse engineering book and trying to follow his RtlInitializeGenericTable example. The first part of it is fairly straightfoward- 7C921A39 MOV EDI,EDI 7C921A3B PUSH EBP ...
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1answer
3k views

Decompile large function in IDA

I'm working on a crack me, specifically: jaunsacco's DragonCrack and the first thing I've gotten stuck on is that the program is built mostly as a enormous main function. After attempting to decompile ...
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1answer
558 views

Are there any Java decompilers accurate enough that if I recompiled the result, it should be identical to the original program?

I am trying to decompile Minecraft, to see if I can analyze the code to make a few small changes, but I need a decompiler good enough so I can recompile it in a way that will work. I have tried ...
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253 views

Calling functions of a shared object (.so) extracted from an APK

Decompiling a regular Android application I noticed that its code uses some native functions. So, unpacking the (.apk) file I found the usual "lib" folder and under that a series of folders for ...
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1answer
260 views

Search string in all binary pesudo-code

How can I search pesudo code string in all functions in binary with Ida?? Pesudo code I mean when press F5 in Ida I can see psedo code of the binary (like in c) I want to search for example where ...
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1answer
806 views

IDA Copy structure from one database instance to another

This question sounds rather simple, but I can't seem to find any option for this. I'm basically re-creating another database instance of the same binary I already reversed and I want to copy some of ...
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1answer
545 views

Can you change the architecture in Ghidra after importing?

I've been analyzing an ARMv7 binary for a while and have done a lot of work with it (e.g. labeling functions, creating structs, labeling globals etc.). Unfortunately, I just realized that Ghidra ...
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1answer
356 views

custom virtual machine protection

How someone would go to reverse engineer a sample protected with a virtual machine? The problem is that it's not opcode anymore it's bytecode which I don't have any idea about because it's a private ...
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218 views

IDA Pro Reset All Stack Pointers to Default

Is there a way letting IDA scan all the database and reset all stack pointers values to it's default state that were previously modified? i.e like it was when I first started the analyzing the binary? ...
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224 views

IDA Hex-Rays Decompiler Generates ASM Code Issue

For a long time now, I've been struggling with some functions generated with IDA HexRays plugin that seem to be corrupted. Some of the decompiled generated plain C code, show as ASM code :/ i.e: ...
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123 views

(Help)Apk Decomplied unreadable files

I'm developing an android-based game for my school project. I chose an .apk to reference the visual parts. I've decompiled the .apk file I've specified. I can't view the image files I need. files ...

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