Questions tagged [assembly]
A family of very low-level programming languages, just above machine code, where each statement corresponds to a single machine code instruction.
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Reverse engineering JCALG/LZ?? compression
I think this is related to this this question, but the consts in the example code don't exist in mine, so maybe it's a different level of compression, but I am unsure.
Can anyone provide me the right ...
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from executable to assembly source code?
let's say i have an ".exe program" and i want to disassemble it and get "disassembled code" .
my question is => can i maintain and organize that "disassembled code" ...
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Trying To Understand DOS Game Assembly Instructions
I am trying to understand assembly language instructions, for a DOS Game.
I have looked at the following Link :- https://atrevida.comprenica.com/atrtut07.html
reading about how VGA Graphics work in ...
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Assembly for malware analysis
I know we have some architectures for assembly language. But I wanna know this: I need learn x86 assembly ? , or arm assembly ? , or both ? , or others ?..
Please help me , what should I learn?
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Is it legal in the US to reverse engineer a product and then share the CAD for free to whoever needs it?
First some background.
I have this 3D printer that sucks, is pretty expensive, and unreliable. Whenever you need a spare part, the manufacturer sells you the entire kit! I needed a thermistor and they ...
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Help Needed With Finding Image Data In DOS Game File
I have been analysing, an File called FW190AS.PAC from a 16 Bit Game called Secret Weapons Of The Luftwaffe, in a Hex Editor, the Bytes are displayed in Little Endian format. My aim with this game, is ...
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How can i remove dead code and opaque predicates?
I have the following problem on my agenda: There is an obfuscated .exe (this is a virus that I am investigating) in addition to having an MBA, etc. bullshit, he has Opaque predicates and dead code, I ...
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Reversing Assembly to C
I've read the open letter addressing students asking for help with their homework and I agree with it, therefore I will try to be less of a pain in the *** ;)
I need to reverse the x86-64 (AT&T) ...
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other than x32dbg, is there a more friendly way to check functions, their args and their return values on runtime?
atm I'm using ida and x32dbg, when I find a function that interests me, I set a breakpoint on x32dbg, however, I'm not good enough at assembly to know everything from a function just from looking at ...
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How can you tell where an assembly function ends?
Finding the start of a function is sometimes obvious - for example if some part of the code has a call foo then foo must be a function.
But what about finding the end of a function? I realize tools ...
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Where is the XOR operation?
I am doing TryHackMe REloaded room, level 3.
When I got stuck I followed this tutorial which mentions an XOR by 7 operation being performed on a string, however I cannot see it anywhere.
Where is it ...
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Change string value when string is in a RAM address x64 c++ program
I'm new to reverse engineering.
I'm simply trying to change the value of a string in x64dbg, of a program I make myself in VS
(It's a c++ program, and is VERY simple; it just prints a string, and two ...
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How to bypass anti debugger? IDA Pro
Im new to reverse engineering and doing a crackme that requires me to make a keygen, yes i know making a keygen isn't a beginner task however im stuborn, i am trying to debug the program to understand ...
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Reverse engineer a blackbox function operating on single or double precision floats for emulation
I own and run a NEC VectorEngine 10C which is a PCIe accelerator running a proprietary ISA which has many fun instructions among them is VRSQRT which computes an approximation of the inverse ...
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why some functions push data before the prologue
i am a newbie in the world of RE ,
i start to explorer a main entry of a classic game from 90's
and i start to see something confuse me as a newbie
this main entry function start with pushing stuff to ...
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What are the prerequisite knowledge needed to start solving crackmes?
I started by reading a book on C language and then moved on to "Programming From Ground Up," which teaches basic programming in x86.
School just ended, I'm working on cracking a game called ...
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Ghidra Shows Structure Strange
I am new to assembly. When I was disassembling some code, I encounter some strange instruction here. The instruction shows that (RBP + -0x40) is equal to local_48, however at the beginning of the code,...
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Why did I have gotten only null bytes argv variable from angr?
I have made simple program to test the angr.
My python code is here.
import angr
import claripy
p=angr.Project('./test2')
buf=claripy.BVS('buf', 8*10)
initial_state=p.factory.entry_state(args=[&...
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Reverse Engineering CTF help
I am having trouble figuring out this microcorruption challenge in the link below: https://microcorruption.com/debugger/Halifax
Basically, the 0x7f interrupt has been disabled so I must reenable it ...
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Reverse engineer a calculation rule from a video game
I have recently bought an economic simulation video game, but neither the docs not the game UI describe how to estimate some costs; the user needs to actually invest and spend their money, then ...
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What was the original math operation after optimizing compiler?
I'm pretty sure that original code was much simpler:
(((x + 16) >> 31) ^ abs(x + 16) & 3) + 4 * ((y + 16) % 4) - ((x + 16) >> 31)
Looks like division with remainder... Any ideas what ...
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What tricks can I use to manually decompile a set of instructions
ELF Binary takes user input and stores it in loc.buffer address 0x4020e8. Further, the registers going into the instruction set are
eax
ebx
ecx
edx
esi
length of user input (min length is 3)
0
...
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ghidra assigns local variable to register
im reversing a android native library and im trying to understand how a token is generated the toke n is passed to a callback java method and i traced where the method is getting called from
this is ...
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Reading memory values in IDA
Want to get 32 bits from 0x8000 adress as 8 bytes
MEM_EXT:00008000 db 54h
MEM_EXT:00008001 db 53h, 57h, 20h
MEM_EXT:00008004 dd 322E3256h, 31332030h, ...
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Overclock CPU in BIOS - ARM/C/C++/Py
new guy here. Working on Bi0S script, adding as many features as possible. It is possible to change fan speeds, advanced security, manipulate voltages, etc. How do you overclock the microprocessor ...
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How to decrypt data during runtime before executing and then encrypting it back
I was doing some research and came across the term protectors. From my understanding is they encrypt a file to be protected but run it without an issue. During its execution it is able to decrypt the ...
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How to call Windows console in ASM and printf some values there?
Is there a working way to embed the windows console in disasm code? I tried AllocConsole with GetStdHandle or AttachConsole with PID of an existing console but it didn't work. I have tried printf ...
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debug stripped file
I've system embedded mips big endian with gdb-server and I want debug stripped file of the target, I can run in target gdb server with stripped file (--attach PID), but when I try to connect with gdb-...
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Unable to understand x86 instruction(s)
Recently I have been given a set of assembly instructions which I must learn to understand. I know an extremely basic level of x86 assembly but I'm starting to come across more nuances that are very ...
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Data placement in memory
I am playing with buffer overflow attacks in C. I have the following code:
int foo(void*, void*); // Calculates the distance (in bytes) between two addresses in memory
int main(int argc, char**...
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Simplifying and reversing an encryption/decryption algorithm in ASM X86 / Python
I'm trying to reverse a decoding function in order to produce the function for encoding (for the curious this is a save game for a legacy adventure game which use codes for saving).
So far I have ...
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What is a "far call" in an x86 or x86_64 cpu
I do not understand the usefulness of the "far call" instruction in a 86 CPU.
On a 32 bits CPU for example each process has an addressing space of 4Gb (0x00000000 to 0xFFFFFFFF).
There can ...
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problem with hooking __usercall function and asm code
I need a hook function with the __usercall convention.
I already hooked functions that were defined as __usercall and __userpurge, but this time it's __usercall with arguments that are also passed ...
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Reversing Assembly Code (ASM) to Extract Password (Pin)
I'm new to binary exploitation and CTF challenges. I need to solve a CTF challenge and find the flag. All the program does is display "Flag length is: 32". I've tried to analyze the file ...
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Can someone help to understand code disassembly by IDA?
Can someone help to understand code disassembly by IDA?
Basically this use for calculate key from seed. Here I would like to understand the logic and also I would like to know what would be the output ...
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X32dbg Stepping through assembly, seems to get stuck on one line and not progress forward, even though the application continues to progress forward
I'm using x32dbg. Stepping through assembly, I get to the following instructions:
'''76B7CC12 | 8B4C24 54 | mov ecx,dword ptr ss:[esp+54] |'''
If I continue to step through ...
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STATUS_PRIVILEGED_INSTRUCTION 0xc0000096 from kernel mode code?
Running a kernel driver I wrote. The driver includes:
mov rax, cr0
btr rax, 10h
mov cr0, rax
to clear WP bit in cr0. Curiously the last instruction faults and causes a bluescreen, ...
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Is there any way to understand if a raw binary firmware is Cortex-M or not?
I have a list of firmwares, and I should filter just the Cortex-M type. Is there any automated way that I can distinguish them from other ARM firmwares?
I have some ideas like Interrupt vector Table (...
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How to find the fifth function argument on stack in windbg?
I know that in x64, the first 4 arguments are passed by RCX, RDX, r8, r9. The rest arguments are pushed on stack. In x64, rsp serves as base pointer(prolog) and frame pointer(epilog) and save value ...
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How do i loop this CreateThread call in Assembly to get 4 threads instead of only one?
Knowledge in C++ Assembly and some reverse engineering experience
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Tuning motor temperature
I have a DC motor, running in two modes, slow and fast. I will need to run the motor in FAST mode only. The motor is already running for 10 years. The motor experiences variable load.
According to the ...
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Reversing Games like Manfred dis
I've looked at as many resources on Manfred and Manfred's work
I've watched the DEFCON 25 Live talk about what he hacked.
Here
I've also looked, listened and read the dark net diaries Part One -
...
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PowerPC disassembly with libopcodes
I want to disassemble Wii game executable binaries in C, which use the broadway microprocessor and unfortunately the only disassembler I am aware that I can use is libopcodes.
I am following this ...
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Assemby reverse engineering
I'm new to assembly and need some help understanding what this program does. This program takes a username and serial. If the combination is correct, it prints the magic words.
I need to write a ...
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Why output is disabled in console when using int3?
I am using NASM(2.15) assembler to generate code. But I am unable to figure out why it does not show output in the console(windows system) when using int3 - software breakpoint, it only shows output ...
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Crackme assistance - unknown function [closed]
i have a problem about a crackme that my friend sent me for a bet. I solved most of it but i am stuck with this function. I can't even understand what the function is trying to do. Please help.
images ...
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Do I have to learn computer architecture for underestanding or doing reverse engineering?
I am completely noob in reverse engineering, and I've just started to learn it.
Now I have this question in my mind, that does a reverse engineer use any computer architecture knowledge for doing his/...
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What does MOV RAX,qword ptr FS:[0x28] mean?
I'm trying to understand what MOV RAX,qword ptr FS:[0x28] means. I get that FS:[0x28] is a stack canary. If my understanding is correct the data from RAX gets copied by MOV. Then there's a comma which ...
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Displacement size (disp_size) of x86 instructions
Given the opcode 80 3d 1d b0 09 00 00.
The corresponding capstone instruction is
<CsInsn 0x66a4 [803d1db0090000]: cmp byte ptr [rip + 0x9b01d], 0>
and has the following properties (c_i being ...
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Missing mnemonics '??' in Ghidra Assembly Code
I was just trying to google and search for "??" Ghidra with no luck.
I am trying to understand what the following questions mean in this Binary (meant for SuperH2 SH-2 processor) which is ...
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