All Questions

Filter by
Sorted by
Tagged with
1
vote
1answer
109 views

Change instruction test eax, eax to text eax, 1

I'm trying to change an instruction in assembly. Try with test eax, eax to test eax, 1. I try modify the opcodes. For example opcode of test eax, eax: 85c0 Try to understand why is 85c0 with this ...
4
votes
2answers
361 views

Inverse And operation

I'm trying to write a keygen to a crack me that I'm learning from and I got stuck. What happens there is pretty simple: Let's say that I entered the password: "12121212" XOR DWORD PTR DS:[ECX+EAX],...
1
vote
1answer
463 views

Understanding the variables in stack layout

i am reading the "The Grey Hat Hacking-The ethical hacker's Handbook".The book is nice ,but there is a doubt on a particular subject.In the vulnerability analysis chapter it is trying to analyze a ...
3
votes
1answer
2k views

xor eax, eax in x64

I have following code: sub rsp, 40 ; 00000028H lea rcx, OFFSET FLAT:$SG4237 call printf xor eax, eax add rsp, 40 ; 00000028H ret 0 Why there is xor eax, eax , ...
1
vote
1answer
571 views

Assembly and C++

I'm trying to learn Reverse Engineering, at this time I compile C++ code without any optimization and see the correspond assembly in IDA's disassembler, but there are some parts of the code, where I ...
3
votes
0answers
162 views

Comparing two UEFI applications?

I have two x86-64 UEFI applications original.efi and patched.efi. I want to find out what have been changed in patched.efi and what these changes do. I have tried to use the Radare2 framework to ...
0
votes
0answers
157 views

How to access and modify data segment when doing hardware breakpoint crashes the application?

I want to modify the data segment in the x64_DBG, however, I don't know how to access it. lea r8,qword ptr ds:[7FEF0CA6AD8] In the above code, the address 7FEF0CA6AD8 is loaded in r8 register. I ...
5
votes
1answer
9k views

How to reverse a dll and call its functions?

I have got a custom.dll which is utilized in a larger application. The application executable imports this dll to use its functionality. But this functionality is not used through out the life cycle ...
0
votes
0answers
682 views

How to change the DLL name in the already compiled application?

I am trying to change the name of the DLL file I had specified for my application before compiling it. When I change the DLL file name I get the error message like: System.IO.FileNotFoundException: ...
1
vote
1answer
107 views

Distinguish between local function calls and external(imported) function calls in a dynamic trace

I know that when IDA pro want to disassemble a binary and label the functions, employs import address table and IDA flirt to distinguish from local functions and external functions! Now I have ...
2
votes
3answers
12k views

Ollydbg does not find all referenced strings while Reverse Engineering AoneVideo2AudioConverter

I am following this tutorial on reverse engineering. In the step where I "search for all referenced strings" I get a window as follows: When compared to the image on the tutorial for the step, I ...
-2
votes
1answer
143 views

How can I do this in less than 10 bytes of space?

I have some value stored at a memory location. I have 10 bytes of space and have following to do: push registers copy a string constant "abcedfghijkl" to that memory location restore registers Is it ...
1
vote
1answer
1k views

IDA Pro breakpoints with side effects

I am trying to set a breakpoint that works by applying a condition. More precisely, I am trying to change the count increment in the AL register by placing a breakpoint condition saying AL = Al - 1 ...