Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [decompilation]

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

0
votes
1answer
55 views

How can I make IDA understand this switch statement with a signed jump table?

I took the following C code and compiled it on Ubuntu 16.04 with GCC 5.4.0: int main() { int a = 0; for (int i = 0; i < 5; i++) { switch (i) { case 0: a = 1; break; ...
0
votes
0answers
27 views

View Data from a .dat file

I am doing working on a project of my own where I am using the data of a football game to calculate certain statistics on players. Long story short, I am having trouble extracting the data from the ...
4
votes
1answer
188 views

Reverse Engineering bios of ATM Machine

I bought an Hyosung NH1500 off Offer-up and it boots up and initializes some peripherals and then spits out and error of "COM download is failed". I've searched Google and 0 results came up, I've been ...
1
vote
0answers
25 views

How to tell when Cor20 starts for DLL's that are supposed to meet ECMA-335?

When I look at a .Net compiled DLL that is supposed to conform to ECMA-335, I see the PE Header well defined up to 0x1EF, but there seems to be block between 0x1F0 and 0x208 which is mainly 00's that ...
1
vote
0answers
28 views

IDA 7 handling strings in debugger pseudocode

When running a remote debugger to a linux server, is there a way to get IDA (7.0) to properly handle strings? When I go to the pseudocode view, I get things like this; v7 = sub_804AD60((std::string *)...
0
votes
0answers
48 views

Multiple decompilation failure with ntoskrnl

IDA v7 shows decompilation failure in 64bit ntoskrnl.exe file of Windows 10 build 18262. Here is an example of that: I've loaded all the needed type libraries, PDB file, kernel mode header files (wdm....
3
votes
1answer
316 views

XCHG RAX, RAX: 0x09, what does this code do and how does it work?

Given the following short assembly snippet: shr rax, 3 adc rax, 0 I worked this out a bit: We know SHR sets the CF with the last bit shifted. We know ADC dest, 0 is just adding the CF. So ...
2
votes
1answer
189 views

Converting Assembly x64 code to C

I have the following code: 0000000000400526 <main>: 400526: 55 push rbp 400527: 48 89 e5 mov rbp,rsp 40052a: 48 83 ec 20 sub ...
1
vote
1answer
93 views

Figuring out what a segment of assembly code does

I have the following assembly code: 0000000000400711 <foo>: 400711: 55 push rbp 400712: 48 89 e5 mov rbp,rsp 400715: 48 89 7d e8 ...
1
vote
0answers
69 views

Need help understanding IDA Pro pseudocode

I am new into IDA and have some questions about the pseudocode in C. Could someone please explain to me the meaning of the following two lines: (*(void (__fastcall **)(int *, _DWORD))(*v1 + 196))(v1, ...
0
votes
1answer
265 views

What does this assembly language program output?

I have been struggling with this for a long time. I have the following assembly language code: .intel_syntax noprefix .bits 32 .global asm0 asm0: push ebp mov ebp,esp mov eax,DWORD ...
4
votes
1answer
137 views

Need help identifying main processor for Roland synthesizer

I desperately need help figuring out the ic chips in this unit so I can view the firmware in ida pro. So the unit is a roland gr-55 guitar synthesizer and i'm trying to disassemble the firmware into ...
0
votes
0answers
40 views

Exception while decompiling C# Windows application

I'm pretty new to RE, decompiling and stuffs. and my first time posting here. Recently I tried de-compiling a Windows app written in C#. I use Just Decompile. The decompiled code however shows some ...
0
votes
1answer
133 views

What is the password to this file? I can't figure it out with radare2 or gdb

Here is the binary file. https://drive.google.com/file/d/1ywN60yZYIhPPRyZMGbQudZRYoLYBhkeJ/view?usp=sharing I am able to figure out some of the assembly, but can't get the correct password. I know ...
0
votes
0answers
87 views

How to change value in IDA pseudocode?

If I press F5in ida, I can see pseudocode. When I debug this pseudocode, I can see values of variables. How can I change the value of specific variable in pseudocode?
0
votes
0answers
217 views

Where is Hasp Sentinel LDK (NO DONGLE) license information stored. H0045

I am trying to hack hasp sentinel LDK and have managed to create a spoofed time service for HASP. At the minute I have a trial which thanks to the crack lasts forever. However, the issue is during ...
1
vote
1answer
680 views

How do the AI in Pokemon battles work?

Has anyone ever attempted to decompile the code for a Pokemon game and figure out how the battle AI works? e.g. How it decides which move to use, or use a Potion/even withdraw based on the current ...
1
vote
3answers
84 views

How to identify the purpose behind a bitmask?

The bitmask is used to manipulate the value of the integer variable. From debugging, I guessed that the bitwise operation generates nearest even integer. Here is the assembly: mov r8d, 0FFFFFFF8h ...
2
votes
1answer
40 views

Do all class instances have a relative address/offset and can i make a copy of any class pointer?

I'm familiar with finding a player base pointer as-well as other values in games, and finding offsets and such. And I have applied that to some of my own code in the past. But does this practice ...
-3
votes
1answer
56 views

Change value of an IF condition found in IDA

so I have the .idb file of an executeable I want to modify. In the IDB file, I found this code And I basically want to change 4111006 to 1006 in that IF condition. however, when I press TAB to go to ...
0
votes
1answer
166 views

Generate c like pseudo code from objdump output

Ida has a feature which generates pseudo code from assembly. Is there a tool under Linux that make the same job, from objdump output for example ?
2
votes
0answers
77 views

Show parameters stored in stack with __fastcall in IDA

This is an extension of my previous question. Here is a sample of assembly in x64 Windows executable using COM virtual function with __fastcall convention. mov [rsp+32], rdx ...
2
votes
1answer
126 views

Android 7.0+ Monitoring application HTTPS requests

I am trying to capture https requests an application performs during runtime without any success yet. Different failing approaches, using mitmproxy / charles proxy and user ca certificates, obtaining ...
1
vote
1answer
149 views

How to find the executable code of the native method in the library * .so? (Android)

I'm doing reverse engineering of a mobile application for android and I had a question how to find the executable code of the native method in the library * .so. From the code of the code, the native ...
4
votes
1answer
141 views

Resolving FLAGS bits with IDA

While disassembling a binary, IDA decompiler decompiles the call as mmap(0x80000000, 4096, 7, 50, -1, 0); While there is nothing wrong with the decompilation itself, it could be more useful to decode ...
0
votes
1answer
129 views

Translating ida macros and pseudocode into C++/C

What would be the translated C output of this hexrays decompiler pseudocode? The values of v6 and v5 are floats just as v8. The value of xmmword_108365D0 is 7FFFFFFF7FFFFFFF7FFFFFFF7FFFFFFFh v8 = (...
2
votes
1answer
188 views

How to unpack Inno Setup bundles with Arc+SREP data?

I've stumbled upon Inno Setup installer with additional separate Arc archives (commonly with .bin extension) that I was unable to extract using normal methods: the installer didn't work for an ...
2
votes
0answers
55 views

Hopper: What does stack[xxxx] mean?

When using the 'decompiler' tool in Hopper on the start function of an application it shows this: What does the stack[2043] mean, is it 2043 bytes from the top of high memory and its assigning it to ...
1
vote
2answers
463 views

IDA Hex-Rays Decompiler : Show strings instead of offset

How can i settings IDA show me string instead of offset_xxx?
4
votes
1answer
127 views

Help understand decompiled IDA code

I got stuck at yellow lines, dont understand what it's gonna do. Need advice or help, thanks! File : https://www.sendspace.com/file/3yowjg Password : 1 void __fastcall sub_A513C0(char *Src, HWND ...
1
vote
0answers
150 views

Decompiling or modifying .exe file generated from .jar

I have one .exe file which is generated from .jar file but I'm not sure how it was made. I cannot open it with winrar or something. I need to modify it or just to decompile it. Any answer should be ...
0
votes
0answers
168 views

IDA: NEC V850. Unable to identify anything

I'm trying to reverse a V850E binary (it was extracted from an official update), however, IDA doesn't recognize anything at all. In order to do that, I select a V850 or V850E1 processor type and ...
1
vote
0answers
41 views

Decompiling DotNet2JScript malware?

I've got a .NET malware sample that was transpiled to JScript using DotNet2JScript. The .NET malware assembly was serialized to binary form using BinaryFormatter and then embedded into the JScript ...
3
votes
1answer
94 views

What are the steps to reverse engineering a Shockwave .DCR file?

I have been fascinated by reverse engineering after making several emulators and finding the pret community. I love the idea behind decompiling old games and recreating source code that recompiles ...
1
vote
1answer
174 views

Would it be possible to reverse engineer a game's rom file to get source code?

More specifically, could you get low level code from a rom, and piece it together and translate it to a higher level language?
5
votes
1answer
515 views

dnSpy - What do these symbols mean?

When decompiling a dll file there are certain lines of code that read like this: return \u0013.\u0002.\u0001(url, info); I have two questions on this: 1) does \u00xx mean that it is obfuscated, if ...
1
vote
0answers
62 views

Reverse engineering IE thick client

Internet Explorer allows for creating thick clients that run in the browser via a Browser Helper Object (BHO). In trying to reverse one such thick client I noticed that the website downloads about ...
3
votes
1answer
95 views

Disassemble/decompile arbitrary JVM bytecode

I have an obfuscated java binary which does runtime code injection using java reflection like this. Object o = "a long string"; ((Method)o).invoke(params..); (If I write this in a java file, it ...
-1
votes
1answer
107 views

Fixing IDA Member functions argument order

When IDA realizes a function relies on the this* pointer it often places as the second variable. Severely mucking up things. I was wondering is there away to fix this and maybe in turn help type ...
5
votes
3answers
553 views

What exactly is binary disassembly and what it produces?

The first time I heard about binary disassembly I thought that it is something what can be called as perfect decompilation tool to assembly code and I still don't understand why it is not. I thought ...
2
votes
1answer
98 views

How to do i fix it when IDA pro mislabels values as loc_

Some times the psuedo code generated by IDA is baffling v8 = (signed int)&loc_100010; //ida v8 = 0x100010; //actual code This is not so bad when it is just one value but sometimes the offset for ...
1
vote
1answer
297 views

De-compiling a random file format to retrieve the files?

Okay. I have a .VRCA file format which I want to retrieve the data from. Where would I need to begin in order to start retrieving data from one of these files. I've read multiple posts that mention ...
0
votes
2answers
312 views

verifyError in youtube android app modification

I try to decompile youtube android application and modify it but when I build the application and install on a virtual device faced with below error: E/AndroidRuntime(1782): java.lang.VerifyError: ...
0
votes
0answers
79 views

C code extraction from binary code

I have binary file from microcontroller MPC5674F - 32bit Power Architecture, e200z7 core. When I open it with hex redactor I see C headers, which I would like to unpack. Tried to open file with IDA ...
1
vote
2answers
712 views

.NET: It's possible to recover original source code from compiled .exe when I have all the .vshost, .pdb and compiled files?

I have the compiled code with all .pdb, vshost and everything that is generated. I am already using DotPeek without too much hassle. Would like to know If I can retrieve the original code with all the ...
1
vote
3answers
317 views

Android- hiding private keys in .so file

I am working on an application where we need to encrypt certain assets at compile time in Gradle. We then need to decrypt them with the same private key, so we are using a symmetric key system but we ...
6
votes
1answer
153 views

How to tell if a particular .NET assembly was written in C# or F#?

The motivation for this question is that I used JetBrains dotPeek to decompile an .exe written in F#, but the output project directory produced C# code. Why does decompiling an F# assembly produce C# ...
1
vote
0answers
176 views

IDAPython Decompile - connect assembly to pseudo-code line

I'm trying to write a small application that can show for each line of the de-compiled psuedo code of a certain function the assembly instruction that responsible for it. for example if we have a ...
1
vote
5answers
214 views

C representation of simple assembly

I have the following very simple X86 assembly: shr cx, 1 jae short <addr> So basically, the jump will be taken if the Carry flag is not set. In the case of shr, CF will be set to the value of ...
1
vote
1answer
105 views

Static Offset in PE

I am making a crackme, that get's hexadecimal values and converts it to ASCII to get the password. The problem is I use a part of code into the main function to search the opcodes from .text section ...