Questions tagged [windbg]
A graphical stand-alone multipurpose debugger for Microsoft Windows, distributed on the web by Microsoft.
150
questions
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1answer
35 views
How much of the kernel does remote kernel debugging allow you to debug?
This is a theoretical question because I've never set up remote kernel debugging before -- but I will do at some point, which should hopefully answer some of the experimental questions I have.
What ...
0
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2answers
54 views
kd live local debugging !pte and db don't work (only shows context of the debugger for all contexts), but !vtop works
Says the PDPT and PDs of the process are at the same physcial frames (pfns) in both processes.
The first process is winword.exe and the second process is calc.exe
The virtual address in the first case ...
0
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1answer
20 views
Defining frame manually windbg
I wonder why defining frame manually keeps failing on range error.
As far as I understand the syntax is :
.frame /c = BASE STACK RIP where if inside MyFunc there is a call OtherFunc, the RIP should ...
0
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0answers
14 views
How to pause a kernel debugee instead of stopping in IDA pro?
While debugging windows kernel with IDA, the problem is i cannot pause it like Windbg, when its running and i click on suspend, 50% of times it just freezes/crashes, and other times it just gets stuck ...
1
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1answer
120 views
How to find encrypted strings in an executable?
I am trying to reverse engineer an executable.
I am using Process explorer to dump all strings present in the exe image, and from the process's RAM when it is running.
The two dumps return a ...
5
votes
1answer
130 views
WinDBG Hung on Shellcode Execution
I've been trying to debug a piece of simple shellcode with Windbg. To go over the steps I took, I allocated a buffer for the shellcode with .foreach /pS 5 ( register { .dvalloc 400 } ) { r @$t0 = ...
1
vote
1answer
49 views
Windbg .thread command is useless?
The ".thread" command is used to change the thread context in Windows kernel debugging.
MSDN
But I encountered the below situation:
Execute the following two commands consecutively.
The ...
2
votes
1answer
58 views
Is there an easier way to break on a rootkit driver load, other than disassembling IopLoadDriver?
The only method i know to break on a DriverEntry of a rootkit driver when its loaded is to disassmble nt!IopLoadDriver and find an indirect call in it and break on it. Setting a break point on ...
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31 views
How to set breakpoint on CreateThread in windbg preview
I have open an executable in Windbg Preview but when I wanted to set a breakpoint on the calling location of the CreateThread API, windbg couldn't resolve the symbol. I have reloaded all symbols for ...
2
votes
1answer
150 views
WinDBG doesn't resolve function names when debugging kernel module
I am debugging a kernel driver. When I set a breakpoint with WinDBG in one of its functions but it doesn't complete the function names while on IDA it shows the names (statically).
Here is a picture ...
1
vote
1answer
89 views
Trying to reverse engineer CmpFindNlsData of winload
I have a basic understanding of assembly language and I'm unable to perfectly define the algorithm of winload!CmpFindNlsData looking at the disassembly. Basically I need to understand how NLS data is ...
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0answers
40 views
Connection to Microsoft Symbol Server reset in windbg
I'm using windbg version 6.12.0002.633 X86 on Windows XP SP3 in a VM. I've configured the environment variable, _NT_SYMBOL_PATH as shown below:
_NT_SYMBOL_PATH=symsrv*symsrv.dll*c:\symbols*http://msdl....
0
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0answers
38 views
Is there an event log to check when WinDbg kernel debugger fails to attach on OS load?
I'm using the latest WinDbg (Preview) to do kernel debugging on a Windows 10 client (v 1909) via a network connection in a VM. And I'm wondering if there's a log that the kernel debugger maintains?
I ...
1
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0answers
27 views
WinDbg pattern search not returning expected result
I'm searching for a string, say the old "This program cannot run".
Switching context to e.g. notepad, non invasive, with page translation
1: kd> !process 0 0 notepad.exe
PROCESS ...
2
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0answers
23 views
Find the caption of VB5/6 Form Object in Memory Dump
I'm looking at a problem with app that has lost source code and the app crashes shortly after calling code that appears to be [Global Variable representing Form Object].ZOrder 0 (i.e. trying to make ...
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33 views
bad memory mapping in case of MEMORY dump IDA <-> WinDbg
when I open the debug dump (IDA x64) , I don't have the memory ranges. Exactly like in this question:
ESP out of range of "Stack View" in IDA
It used to be fine, but I don't have the menu ...
2
votes
1answer
125 views
Get return address from syscall
I'm debugging some 32-bit process using windbg kernel debugger. This process calls some syscalls, so I set few breakpoints at kernel functions like nt!NtQuerySystemInformation. So after breakpoint hit,...
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1answer
177 views
Windbg: “gu” command inside of a breakpoint causes warning
I'm trying to leverage "gu" command in a conditional breakpoint or as a "CommandString" in a regular breakpoint. For example let's consider break on a malloc() function when we want to see in logs ...
1
vote
1answer
201 views
Getting NTSTATUS 0xC0000022 when attempting to debug a process
I am attempting to debug a process with windbg (with admin privileges) and I am getting the following error:
Could not attach to process XXXX =, NTSTATUS 0xC0000022
{Access Denied} A process has ...
0
votes
1answer
558 views
How to calculate the size of a PE from headers?
What I am trying to do is calculate the size of a PE through it's headers. I am using WinDbg's Javascripting and in this case, it will mostly be for drivers. The idea is to dump a driver from memory ...
-1
votes
1answer
106 views
How to find each interrupt's line in the Interrupt Descriptor Table
I'm trying to find the line number of the 0f05 syscall interrupt with no success.
I searched everywhere and couldn't find any way of doing that, it seems like this information is hard coded in the ...
0
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2answers
182 views
Disassembling only given function
I'm looking for some disassembler that has feature similar to WinDbg uf function, it produces output that is really easy transferable to compilable NASM listing. The problem with WinDbg is that it's ...
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0answers
151 views
Issues with Symbols when running windbg on windows xp sp3
I have been trying to debug a crash using windbg on windows xp sp3. I have been getting the below error while trying to debug. I googled around and found the Microsoft no longer offers symbols exe as ...
0
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1answer
559 views
Remote debugging using IDA, connecting to windbg server (kernel mode)
I do kernel debugging by using a virtual com port. One machine (host) is debugging the other machine. I have a remote machine that has IDA, and I wish to connect to the debugging session in the host ...
0
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2answers
81 views
Predicting Memory locations of arguments within a function
I'm trying to write a script that would help display the memory contents of the arguments passed within a function. For example, in the function below, the first argument starts at the EAX register. ...
1
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1answer
51 views
What does -c mean in this Windbg Command Syntax?
kd> u win32k!impPsIsThreadTerminating+0xe4-c L5
| \ \ \ \ \
/ \ \ \ \ \
/ \ \ \ \ \
...
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2answers
1k views
x64dbg (x32dbg) log registers every step like windbg
So I just switched to x64dbg (really using x32 atm) from windbg and so far I like it but the one thing I'm missing is windbg printing all the registers every step in the command window. Anyone know ...
1
vote
1answer
231 views
Setting a conditional kernel breakpoint in WinDbg grinds the debuggee OS to a halt
My setup:
Debugger: Win10 Pro, WinDbg Preview v.1.0.1904.18001
Debuggee: Win7 Pro (running in a VM using VMWare Workstation)
I'm trying to follow the SendMessage call from the user space:
Into the ...
1
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1answer
5k views
How to configure IDA to load .pdb files from Microsoft public symbol server?
I've done this in one VM but I can't seem to replicate it in another. I'm using IDA to analyze a 32-bit Windows PE file. I then want to step thru it with a WinDbg debugger from within IDA.
So when I ...
0
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1answer
164 views
How to call WinApi from a breakpoint in IDA Pro?
When I'm stepping through a debuggee process with IDA+WinDbg (as a debugger), I need to track one parameter by executing the following API (from within the breakpoint):
//C++ code
SCROLLINFO s;
s....
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1answer
359 views
Analyzing Windows kernel driver
I'm trying to analyze some Windows kernel driver. What I want to achieve is full execution trace, from driver entry to end point. Driver is heavily virtualized and contains multiple anti-debugging ...
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0answers
56 views
WinDbg does not shows all first chance exceptions
I have an application, which sometimes fails. I run procdump and see some first chance exceptions like this:
[14:29:38] Exception: E06D7363.?AVCServicesMDException@@
[14:29:38] Exception: E06D7363.?...
2
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2answers
1k views
windbg - Why does the GS register resolve to offset 0x0?
I'm trying to understand how to resolve segment addressing (specifically the GS register in X64).
My toy program:
int main()
{
unsigned long long x;
__debugbreak();
x = __readgsqword(...
1
vote
1answer
778 views
windbg - What is the relation between the VAD (!vad), the PTEs (!pte), and loaded modules and sections (lm and !dh)?
[cross-posted (but closed the original) from https://stackoverflow.com/q/55438806/254959]
I'm trying to gain a better understanding on Windows process memory, and have some gaps with regards to the ...
6
votes
1answer
651 views
Detecting protected processes and critical processes from windows driver
I've got a driver that tamper user-space processes by sending APC calls upon process start using the call PsSetCreateProcessNotifyRoutine.
I wish to avoid tampering with any process that is critical ...
3
votes
1answer
655 views
How to use windbg to view assembly code of kernel function?
I am using windbg for local kernel debugging. I want to view the disassembly of a kernel function (eg. AuxKlibQueryModuleInformation). I am not familiar with kernel debugging. Please help me do this.
2
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1answer
798 views
Debugger Win32 Local vs WinDbg in Ida vs Ollydbg
When I do dynamic analyze of exe file I have few option , and I want to know what are the advantages and disadvantages.
I know that Ida designated for static analyze , but there are some debugger in ...
2
votes
1answer
169 views
Why IDA can't find the function named by windbg
This is definitely a beginner question,I'm doing static and dynamic analysis on certain dll file and the WinDbg give me call stack like
SERVER+0x78123
When I return back to IDA to see the code ...
1
vote
1answer
73 views
Windbg Break Points
I need to set a break point when a specific module address space is being overwritten? I need to specify this by module name not address space
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1answer
104 views
Windbg's “dt” equivalent in IDA?
I wanted to ask whether there is a simple way to see an object's structure (like windbg's "dt" command equivalent)?
Assuming of course I have the pdb file.
Thank you :)
4
votes
2answers
102 views
Are some special chars(<>) in function names not supported by windbg/cdb?
I have a function in a binary like this class<class1::class2>::function. I can't directly use commands like bp, u, x on the function. The only option I have right now is x class* and then look ...
0
votes
1answer
991 views
How to breakpoint atached process with ida when move on
In IDA pro, there is an option to attach to a process using the WinDbg backend.
When I want is to see the process' control flow when the IDA attaches to it.
The only way (that I know) to see the ...
2
votes
0answers
90 views
Ignore some locations in Windbg Conditional breakpoints
I'm trying to set a conditional hardware breakpoint on Windows Kernel-Mode in Windbg by using the following syntax :
ba w1 ffff802312345678 "j(@rip==ffff802387654321 || @rip==ffff802387654330) 'gc';''...
2
votes
2answers
1k views
What is the difference between Windbg and local debugger in IDA
When I want to debug an .exe on Windows with IDA I can choose between Windbg or local debugger.
What is the difference?
By the way, is there any difference if I use Windbg tool (windows software) ...
3
votes
1answer
761 views
Question about the limit and base address in x86-64 segmentation model?
I'm trying to understand how segmentation works under x86-64. From what I see, it's mostly disabled, but not entirely. It looks like GS and FS registers are still using it.
So I was reviewing the ...
2
votes
2answers
999 views
Can I set more than 4 memory access breakpoints in WinDbg?
I can set a DWORD memory read/write access breakpoint in WinDbg with the following command:
ba r 4 0x0307F42C
But is there a way to set more than 4 of those?
4
votes
0answers
880 views
Windows 10 v.1803 boot failure after trying to install network kernel debugging with WinDbg Preview
I'm trying to set up kernel debugging on a physical hardware/desktop to test the new WinDbg Preview. Here's the steps:
I'm using a desktop with Intel DG41TY board.
Installed Windows 10 Pro build 1803....
1
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0answers
161 views
Prevent windbg from context switching when stepping into assembly instructions
When I'm using Windbg (in kernel mode) to step into assembly, I would encounter context switching once in a while - which is annoying.
So, for example, I placed a breakpoint for a process - let's ...
2
votes
3answers
1k views
WinDbg: Setting a breakpoint on every EXPORTED function of a module
Kinda new to WinDbg. I got an executable who loads a module later in the execution path, so at start I'm doing sxe ld:moduleName to break when the process loads the module.
Then I tried to just put a ...
2
votes
1answer
865 views
Windbg: How to directly view GS:[0x60]
Win10x64: In Windbg, how may I view a pointer to the PEB by directly using GS:[0x60] (and not by Windbg extensions)?
To test, I assembled a program via masm64 that throws an interrupt, clears r8 then ...
