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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 it possible to recover the key to a decrypted file?

Is it possible to recover the key to a decrypted file if you have the initialization vector and it uses RijndaelManaged? If so how? The file I want to recover the key from is a xml that looks like ...
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1answer
1k views

Assistance in Decrypting Lua script that is obfuscated with Base64 > SSL

Can anyone on here help me on decrypting the SSL encryption that protects this LUA script linked at the end of this topic ? Basically they are encoded with Base64 then SSL, but I have no idea how to ...
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1answer
40 views

De-obfuscating code ran through JScrambler 3x via Eval() functions

I am relatively new to JS and de-obfuscation in general and I am having difficulties reversing some complicated JS. I know the code itself is obsfucated via jscrambler 3-4x and therefore is ran ...
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52 views

Can I define custom enum-type to be used in Ghidra as a data type?

I'm trying to learn Ghidra. Say, if it generated the following code for loading functions from an array of function names from gpfnCommCtrlAPI: I was able to retype gpfnCommCtrlAPI into char*[14] ...
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35 views

deobfuscating/decompiling extremely complicated javascript [on hold]

I am working with some extremely complicated JavaScript. It is around 70,000 lines long and sections of the code look like this U2xx.l11="0x78920d50";m2xx.r9G="11";b2xx.v3y="0x744ebc37";P2xx.K5h="...
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1answer
108 views

Unable to decompile C Code

Recently, i have gone through some kind of win32-64 executable files which can't be decompiled under IDA (into Pseudocode). Only the Assembly Code can be read. When i try to press F5 to decompile the ...
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0answers
143 views

How to load symbols from a symbol server in Ghidra?

I've been trying to learn Ghidra by attempting to reverse the comctl32.dll system library, which has many of its functions documented. I started the de-compilation analysis in it, and after a while it ...
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1answer
102 views

How can I convert the following assembly code to pseudo code?

I got the following disassembly code in IDA pro. I really find it hard to convert it into pseudo code. push ebp mov ebp, esp sub esp, 14h mov dword ptr [ebp-14h], 1 mov dword ptr [ebp-10h], 2 mov ...
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1answer
93 views

Decryption loops

I'm reversing a CTF binary and I found a decryption loop decompiled by IDA like this: for ( i = 0; i < n; ++i ) { v22 = *((_BYTE *)sub_5657D89B + i); v0 = v22 ^ 0x90; v1 = strlen(&...
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1answer
101 views

Is there any decompiler, which can produce a compilable result?

I would like to decompile a 32bit linux executable to C, modify some parts of it, and then compile it back. I do not care if the C code is not pretty and really hard to maintain. The only thing I care ...
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1answer
300 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 ...
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25 views

Is there any way to execute Hopper scripts from command line?

What should I do if I have a batch of binaries to decompile with Hopper? I know how to run a Hopper script in the UI interface, is there any way to run Hopper scripts from command line? Or any other ...
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2answers
5k views

Mapping Android resource IDs to resource string

I'm trying to reverse engineer an Android app. I've tried using several decompilers, and while I'm getting java source codes to varying levels of accuracy, I'm not able to convert the resource IDs to ...
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52 views

How to decompile these LUAs from the Bookworm Adventures games?

I'm trying to decompile the LUCs (customly extensioned LUAs) from both of the games but they won't decompile, they aren't encrypted and use LUA version 5.0.2 (32-bit) according to the game's code. ...
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38 views

Taking a luac file and making a modification

I have a luac file for a program I use. I'd like to make a modification to this file to call a function from another luac script. My understanding of the way luac works is the first few bytes are the ...
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3answers
4k views

How to decompile a C# .exe on macOS?

It this even possible? Are there any free tools?
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1answer
109 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....
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1answer
48 views

Calculate LEA operand

I have those opcodes on 64 bits: 48 8D 35 45 CE FF FF >>> lea rsi, [rip - 0x31bb]. How can I get the 0x31bb value from those opcodes and how can I know if I have a + sign or a - sign ...
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1answer
704 views

Understanding AutoIT “compilation”

I'm trying to de-compile a cheat created for my game so I can fix it. The problem is the version used is 3.3.14.2 which no longer has official de-compiler support. I have tried looking for 3rd party ...
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2answers
476 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: ...
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1answer
305 views

Impossible to execute a program with radare2 : TO DO continue

I am trying to crack a crackme. I already catch the flag because I seen the string variable which represants flag. I would like to catch the flag on an other way, I want to set a breakpoint when there ...
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0answers
107 views

Reconstruct InnoSetup file with existing CompiledCode.bin

Is it possible to somehow re-compile/reconstruct Inno Setup file and use existing CompiledCode.bin ? I dont have the source of CompiledCode.bin and writing from scratch is not an option. Basically ...
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1answer
204 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; ...
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1answer
4k views

Hex Rays - strange functions __ROL4__ and __ROR4__

What's purpose of functions ROL and ROR? For both of them, first arg is int, and second is byte I suppose that's bitwise shifts ]1s]2
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1answer
265 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 ...
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6answers
45k views

Decompiling .pyc files

Does anybody have a suggestion for (non commercial) software to decompile "byte-code" Python (.pyc) files? Everything I've found seems to break...
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0answers
28 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 ...
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0answers
100 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 *)...
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1answer
416 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 ...
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3answers
174 views

Running just one function from an compiled executable or shared object?

Radare lets me view the assembly and pseudo-C code of a function. Can I run those instructions though outside of the process? Perhaps setting the register myself? If so, how would I go about doing ...
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1answer
116 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 ...
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1answer
299 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 ...
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0answers
95 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, ...
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1answer
782 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 ...
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1answer
213 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 ...
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1answer
219 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 ...
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1answer
75k views

Decompiling iPhone App

I've been searching this site and more, but I haven't had much luck. I want to decompile an app to see how part of it works, and I've tried multiple programs. I've tried Hopper, IDA, and some other ...
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1answer
297 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 ?
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3answers
117 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 ...
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1answer
911 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 ...
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7answers
92k views

What is a good Java decompiler and deobfuscator?

I am using JD-GUI to decompile Java JAR files, but the problem is that it leaves many errors, such as duplicate variables which I have to fix myself and check to see if the program still works (if I ...
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1answer
49 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 ...
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1answer
106 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 ...
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4answers
12k views

Recovering .NET sources into full blown project

I wonder if total decompilation of arbitrary non packed project .NET is possible? If no, what is the conditions that should be met to make it possible? If yes, is there tools that can automate this? I'...
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0answers
105 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 ...
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1answer
164 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 ...
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1answer
301 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 ...
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2answers
481 views

Android App's hardcoded local keystore password r3versing

Novice Android security researcher here. Recently I was tasked with the task/challenge of exposing a certain app's hardcoded local keystore password. I've decompiled it with JEB2 and obviously within ...
4
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1answer
282 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 ...
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1answer
163 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 = (...