Questions tagged [decompilation]
Process of translating assembly code extracted from a binary file in a structured programming language, such as C.
353
questions
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2answers
71 views
How would I start to decode this? Asking for help from a friend (Alien Hominid Invasion)
I have literally no idea how to start to decode this kind of a file, but I really want these fonts and a decoder would be huge for the community, so any help would be great. Linked below is a google ...
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votes
1answer
56 views
Is decompilation easier or generally more accurate for smaller ISAs?
I am wondering if decompilation would be easier for an ISA with fewer instructions. For example, RISC-V vs x86.
0
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2answers
91 views
Is manually converting/decompiling x86 source code to C/C++/etc… considered reverse engineering?
I have the source code of an old program written in 32-bit x86 assembler that I am working on manually rewriting in C.
The first time someone asked me about this project I told them I was 'reverse ...
0
votes
1answer
74 views
How to make Ghidra recognize bit fields?
Suppose we have the following C source:
typedef struct {
int bit0 : 1;
int bit1 : 1;
int bit2 : 1;
int bit3 : 1;
} bit_struct;
bit_struct a;
void setBit3()
{
a.bit3 = 1;
}
When we compile ...
2
votes
0answers
36 views
Ghidra is mishandling a field access
I have a program which decompiles in Ghidra to include the line
temp_5f2f2f81bc = *(CPedIntelligence **)(&DAT_000010c0 + (longlong)pCVar2);
temp_5f2f2f81bc is a CPedIntelligence*. pCVar2 is a ...
2
votes
1answer
117 views
How do we decompile java so easy?
I have seen a lot of videos where everyone is decompiling the jar files so easily. but I learnt that we cannot decompile any compiled file so easily. I have a little bit of experience in Gidhra. I ...
1
vote
2answers
162 views
Batch decompile using IDA Pro 7.5
I am trying to batch disassemble and decompile 500 binaries using the IDA Pro 7.5 disassember and Hex rays decompiler. I can get the .i64 output from the disassembler, but I do not have a way to batch ...
5
votes
2answers
177 views
What kind of function creates this code pattern?
Apologies if this is a duplicate. Don't know what words to search for as that's what the question is about.
I'm relatively new to reverse engineering binaries and while using Ghidra I've noticed that ...
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votes
1answer
102 views
How can I analyze this code? [closed]
I wanted to analyse the code for some functionality.
in my understanding the code contains a logic handling intents with extras. I want to know how these Works! and also how can I pass extras using ...
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votes
1answer
113 views
How to reverse engineer apks? [closed]
is it possible to reverse engineer an apk just to unlock hidden/unreleased features?
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1answer
68 views
Is Ghidra's decompilation of ARMv7 strb.w instruction broken?
I'm currently disassembling some firmware, when I stumbled across the following code snippet produced by Ghidra (the names are already my own ones):
void memset(byte *addr,byte value,int count)
...
2
votes
1answer
193 views
How to prevent Ghidra from removing unreachable blocks?
I am using this extension for loading PS-X executables:
https://github.com/lab313ru/ghidra_psx_ldr
During decompilation, Ghidra shows some of these warnings:
WARNING: Removing unreachable block (...
1
vote
1answer
60 views
Issue understanding simple ARM ASM function
I'm a little stuck trying to understand this simple piece of code. It get's a number in R0. The first part seems to be a R0 = abs(R0), but then it get's more difficult. The number of leading zeros is ...
1
vote
0answers
56 views
Removing/bypassing a BIOS whitelist
I am trying to bypass or erase the BIOS whitelist on my Thinkpad T440p. So far I've
used flashrom and a soic8 clip to dump the bios to a bios.img file
made another dump and compared with diff bios....
0
votes
0answers
127 views
What are the known techniques used by wrappers and obfuscators to protect against decompiling?
I am NOT looking to make my application 99% safe, nor my goal is to prevent a a determined reverse-engineer to disassemble it, but simply is to protect my source code from lambda user with little ...
0
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0answers
710 views
Reversing Pyarmor Discussion
Anyone messing around with pyarmor recently? For those of you that are unaware of what pyarmor is, its a protection software that is to help obfuscate and protect your software. Heres an image of what ...
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1answer
68 views
how to infer data type in ghidra decompilation result
how to infer data type in ghidra decompilation result for /usr/bin/ls ?
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2answers
106 views
asm snippet to pseudo-code
I'm looking into a way to generate pseudo-code from snippet of assembly,
let's assume I have this ASM
push rbp
mov rbp, rsp
mov DWORD PTR [rbp-4], edi
mov DWORD PTR [...
1
vote
2answers
134 views
How to decompile /usr/bin/ls
How to decompile the following assembly instructions ?
Note: this could be reproduced using /usr/bin/ls binary inside ghidra
2
votes
1answer
59 views
Ghidra Python - cancel decompilation task
The way to decompile a function in Ghidra Python is:
decomp = DecompInterface()
decomp.openProgram(currentProgram)
decompile = decomp.decompileFunction(func, 1000, monitor)
However, in ...
0
votes
0answers
53 views
Force gcc to use more complex instructions
I am reverse engineering a piece of assembly. I am trying to write the equivalent code in C, however, when I compile my code, gcc prefers to use simple instructions instead of the complex ones that ...
4
votes
1answer
251 views
How to improve Ghidra decompilation of SSE instructions?
In practicing Ghidra on a few standard library functions in some executable, I have generally had trouble getting good decompilation output where SSE registers are used as an optimization. I've tried ...
1
vote
2answers
106 views
Working with strong obfuscated Java
I've got a jar file, that is strong obfuscated.
When I tried to put it into decompilers such as bytecode-viewer and luyten I seen many lines of traps and Chinese letters.
I tried to deobfuscate it ...
1
vote
0answers
92 views
Fixing ghidra decompilation
i am working a little bit with Ghidra.
My assembly code doesn't match with the decompiled code:
* FUNCTION *
...
1
vote
1answer
80 views
What code produces FuncInfoV1 with zero TryBlocks and zero UnwindMap?
Topic is C++ exceptions internal representation in WIndows x86 binaries compiled with msvc.
I've found a code that straight up doesn't have nothing (all fields of FuncInfo zero) except the EHFlags ...
1
vote
3answers
120 views
inspecting c-sky elf application
I am new to reverse engineering , but as I am home these days , I wanted to hack my sat receiver
the receiver is based on c-sky v1 architecture
searching forums , I managed to get the firmware ...
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votes
1answer
50 views
Automatic decompilation from Assembly x86
Is there a tool to automatic decompile an assembly x86 code?
What I need is a tool where I simply paste my code and it returns C code.
Thanks
0
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0answers
152 views
Ghidra wrong array size
I'm new to the field, so it's probably a stupid question, but when I tried to decompile this binary from picoCTF 2019 I got an array of size 4 (local_38) when looking at a solution it should be of ...
0
votes
1answer
98 views
Ghidra Python - Get Decompile Line Text by RVA
Is there a way in Ghidra Python to get the corresponding decompile line by RVA?
Or the opposite - get the corresponding RVA from a given line in a decompile?
2
votes
1answer
72 views
Find password in a c compiled binary file
I'm currently learning to do some basic reverse engineering of binary files using Cutter. The program i'm struggling on test if the password entered as argument is correct, if not, return an error ...
0
votes
1answer
44 views
structures defined on stack?
While reading this paper on type recovery from executables, I came across following paragraph:
It is worth noting that the domain of parameters of a function can be
considered as a structure ...
0
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0answers
183 views
What are good tips to reverse engineering code with no variable name information and loss of the debug information?
I am a exploiter for roblox which mean that I execute scripts via an external program called an exploit on running roblox games. To make script for my exploits, I have to use debugging library and ...
0
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1answer
80 views
“check:” keyword in Ghidra
I have disassembled the crackme0x06 challenge (http://security.cs.rpi.edu/courses/binexp-spring2015 inside challenges.zip). It's an ELF 32bit unstripped binary. The decompiled C code using Ghidra ...
0
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0answers
95 views
IDA/Hexrays: local variable allocation has failed; how to fix this?
I'm reverse engineering an old DOS game that's using the DOS/4GW extender. The game includes some libraries that I already successfully reversed in a different application, so I'm pretty sure that the ...
0
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1answer
90 views
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 "...
0
votes
1answer
54 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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1answer
51 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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0answers
205 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 ...
2
votes
1answer
800 views
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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votes
1answer
1k views
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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0answers
59 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 ...
1
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0answers
123 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 ...
0
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1answer
73 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 ...
2
votes
0answers
103 views
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 ...
1
vote
2answers
144 views
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 ...
0
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2answers
256 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 ...
1
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1answer
532 views
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 ...
2
votes
2answers
53 views
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 ...
1
vote
1answer
179 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 ...
0
votes
3answers
545 views
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 ...
