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  #1  
Old 03-04-2025, 04:55
wx69wx2023 wx69wx2023 is offline
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from chatgpt:
When analyzing a process dump from procdump, the dumped file is not a standard executable but a memory snapshot. Because of this, IDA won’t automatically find an entry point like it does with a PE file. Here’s how you can locate the entry point manually:

1. Check the PEB for the Entry Point

The Process Environment Block (PEB) contains information about the loaded executable, including the entry point. You can find this in the dump:

Open the memory dump in IDA.

Locate the PEB structure in memory (usually at fs:[0x30] in 32-bit processes or gs:[0x60] in 64-bit).

Find the ImageBaseAddress and EntryPoint fields.


Alternatively, if you have a full memory dump, you can use WinDbg:

!peb

This will display the PEB, including the entry point of the main module.

2. Manually Locate the Main Module

Since procdump often saves only a specific memory region, the process image base might not be at its usual location. To find it:

Identify memory regions mapped with MEM_IMAGE using a debugger (e.g., Process Hacker).

Look for the main executable module (not DLLs).

Find the MZ (4D 5A) and PE (50 45 00 00) headers.


3. Extract and Reconstruct the PE

If the entry point is missing due to a partial dump:

Try reconstructing the PE header with tools like PEBear or RebuildPE.

Manually fix section alignments based on loaded memory regions.


4. Find Common Initialization Functions

Even without the entry point:

Look for functions like main, WinMain, or DllMain.

Check for imported functions like GetCommandLineA/W, CreateProcess, or NtQueryInformationProcess.


5. Use a Debugger to Find Execution Flow

If you can run the original process:

Attach a debugger (x64dbg, WinDbg) and set a breakpoint at NtCreateThreadEx or LdrpInitializeProcess.

Dump the memory with a tool that preserves execution context (scylla, Process Dump, or PE-sieve).
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  #2  
Old 03-04-2025, 21:57
rcer rcer is offline
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Quote:
Originally Posted by wx69wx2023 View Post
from chatgpt:
When analyzing a process dump from procdump, the dumped file is not a standard executable but a memory snapshot. Because of this, IDA won’t automatically find an entry point like it does with a PE file. Here’s how you can locate the entry point manually:

1. Check the PEB for the Entry Point

The Process Environment Block (PEB) contains information about the loaded executable, including the entry point. You can find this in the dump:

Open the memory dump in IDA.

Locate the PEB structure in memory (usually at fs:[0x30] in 32-bit processes or gs:[0x60] in 64-bit).

Find the ImageBaseAddress and EntryPoint fields.


Alternatively, if you have a full memory dump, you can use WinDbg:

!peb

This will display the PEB, including the entry point of the main module.

2. Manually Locate the Main Module

Since procdump often saves only a specific memory region, the process image base might not be at its usual location. To find it:

Identify memory regions mapped with MEM_IMAGE using a debugger (e.g., Process Hacker).

Look for the main executable module (not DLLs).

Find the MZ (4D 5A) and PE (50 45 00 00) headers.


3. Extract and Reconstruct the PE

If the entry point is missing due to a partial dump:

Try reconstructing the PE header with tools like PEBear or RebuildPE.

Manually fix section alignments based on loaded memory regions.


4. Find Common Initialization Functions

Even without the entry point:

Look for functions like main, WinMain, or DllMain.

Check for imported functions like GetCommandLineA/W, CreateProcess, or NtQueryInformationProcess.


5. Use a Debugger to Find Execution Flow

If you can run the original process:

Attach a debugger (x64dbg, WinDbg) and set a breakpoint at NtCreateThreadEx or LdrpInitializeProcess.

Dump the memory with a tool that preserves execution context (scylla, Process Dump, or PE-sieve).
Very in-depth & useful information, which will require a little bit of time for me to digest & absorb. Will look into this & will revert
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  #3  
Old 03-06-2025, 23:46
rcer rcer is offline
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Quote:
Originally Posted by wx69wx2023 View Post
from chatgpt:
When analyzing a process dump from procdump, the dumped file is not a standard executable but a memory snapshot. Because of this, IDA won’t automatically find an entry point like it does with a PE file. Here’s how you can locate the entry point manually:

1. Check the PEB for the Entry Point

The Process Environment Block (PEB) contains information about the loaded executable, including the entry point. You can find this in the dump:

Open the memory dump in IDA.

Locate the PEB structure in memory (usually at fs:[0x30] in 32-bit processes or gs:[0x60] in 64-bit).

Find the ImageBaseAddress and EntryPoint fields.

.
Maybe I am missing something (or everything), but when I load the memory dump into IDA, I see the following:

seg000:00000000 ;
seg000:00000000 ; +-------------------------------------------------------------------------+
seg000:00000000 ; | This file was generated by The Interactive Disassembler (IDA) |
seg000:00000000 ; | Copyright (c) 2024 Hex-Rays, <[email protected]> |
seg000:00000000 ; | License info: 48-0000-0000-00 |
seg000:00000000 ; | TOM_RUS |
seg000:00000000 ; +-------------------------------------------------------------------------+
seg000:00000000 ;
seg000:00000000 ; Input SHA256 : 50CFFADE61B2095CA37D84FDAB1DCE4D5809D19208C0DC92102DD283132900D0
seg000:00000000 ; Input MD5 : 943FDC8ECCA542FAF3666B8A0E2ABCF4
seg000:00000000 ; Input CRC32 : 253FA370
seg000:00000000
seg000:00000000 ; File Name : E:\01-Support\01-Hardware\Rohde & Schwarz\03-Signal Generators\SMU200A\RCE\ComponentEnvironmentServer_240530_195655.dmp
seg000:00000000 ; Format : Binary file
seg000:00000000 ; Base Address: 0000h Range: 0000h - 1504CE2Fh Loaded length: 1504CE2Fh
seg000:00000000
seg000:00000000 .686p
seg000:00000000 .mmx
seg000:00000000 .model flat
seg000:00000000
seg000:00000000 ; ===========================================================================
seg000:00000000
seg000:00000000 ; Segment type: Pure code
seg000:00000000 seg000 segment byte public 'CODE' use32
seg000:00000000 assume cs:seg000
seg000:00000000 assume es:nothing, ss:nothing, ds:nothing, fs:nothing, gs:nothing

So IDA only lists cs:seg000, but no segment fs:
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