Getting another process command line in Windows

user_193776 0
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I am trying to get another process' command-line parameters (on WinXP 32bit).

I do the following:

hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ | PROCESS_TERMINATE, FALSE, ProcList.proc_id_as_numbers[i]);

BytesNeeded = sizeof(PROCESS_BASIC_INFORMATION);
ZwQueryInformationProcess(hProcess, ProcessBasicInformation, UserPool, sizeof(PROCESS_BASIC_INFORMATION), &BytesNeeded);
pbi = (PPROCESS_BASIC_INFORMATION)UserPool;

BytesNeeded = sizeof(PEB);
res = ZwReadVirtualMemory(hProcess, pbi->PebBaseAddress, UserPool, sizeof(PEB), &BytesNeeded);
/* zero value returned */
peb = (PPEB)UserPool;

BytesNeeded = sizeof(RTL_USER_PROCESS_PARAMETERS);
res = ZwReadVirtualMemory(hProcess, peb->ProcessParameters, UserPool, sizeof(RTL_USER_PROCESS_PARAMETERS), &BytesNeeded);
ProcParam = (PRTL_USER_PROCESS_PARAMETERS)UserPool;

After the first call, pbi.UniqueProcessID is correct.

But, after calling ZwReadVirtualMemory(), I get the command-line for my process, not the requested one.

I also used ReadProcessMemory() & NtQueryInformationProcess(), but get the same result.

Can anybody help?

On this forum thread, it is said that this code works. Unfortunately, I do not have access to post on that forum to ask them.

winapi process command-line windows c++
5 Answers

I was trying to do this same thing using mingw & Qt. I ran into a problem with "undefined reference to CLSID_WbemLocator". After some research, it seems that the version of libwbemuuid.a which was included with my version of mingw only defined IID_IWbemLocator but not CLSID_WbemLocator.

I found that manually defining CLSID_WbemLocator works (although its probably not the "correct" way of doing things).

The final working code:

#include <QDebug>
#include <QString>
#include <QDir>
#include <QProcess>
#define _WIN32_DCOM
#include <windows.h>
#include "TlHelp32.h"
#include <stdio.h>
#include <tchar.h>
#include <wbemidl.h>
#include <comutil.h>

const GUID CLSID_WbemLocator = { 0x4590F811,0x1D3A,0x11D0,{ 0x89,0x1F,0x00,0xAA,0x00,0x4B,0x2E,0x24 } }; //for some reason CLSID_WbemLocator isn't declared in libwbemuuid.a (although it probably should be).

int getProcessInfo(DWORD pid, QString *commandLine, QString *executable)
{
    HRESULT hr = 0;
    IWbemLocator         *WbemLocator  = NULL;
    IWbemServices        *WbemServices = NULL;
    IEnumWbemClassObject *EnumWbem  = NULL;

    //initializate the Windows security
    hr = CoInitializeEx(0, COINIT_MULTITHREADED);
    hr = CoInitializeSecurity(NULL, -1, NULL, NULL, RPC_C_AUTHN_LEVEL_DEFAULT, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE, NULL);
    hr = CoCreateInstance(CLSID_WbemLocator, 0, CLSCTX_INPROC_SERVER, IID_IWbemLocator, (LPVOID *) &WbemLocator);

    //connect to the WMI
    hr = WbemLocator->ConnectServer(L"ROOT\\CIMV2", NULL, NULL, NULL, 0, NULL, NULL, &WbemServices);
    //Run the WQL Query
    hr = WbemServices->ExecQuery(L"WQL", L"SELECT ProcessId,CommandLine,ExecutablePath FROM Win32_Process", WBEM_FLAG_FORWARD_ONLY, NULL, &EnumWbem);

    qDebug() << "Got here." << (void*)hr;
    // Iterate over the enumerator
    if (EnumWbem != NULL) {
        IWbemClassObject *result = NULL;
        ULONG returnedCount = 0;

        while((hr = EnumWbem->Next(WBEM_INFINITE, 1, &result, &returnedCount)) == S_OK) {
            VARIANT ProcessId;
            VARIANT CommandLine;
            VARIANT ExecutablePath;

            // access the properties
            hr = result->Get(L"ProcessId", 0, &ProcessId, 0, 0);
            hr = result->Get(L"CommandLine", 0, &CommandLine, 0, 0);
            hr = result->Get(L"ExecutablePath", 0, &ExecutablePath, 0, 0);

            if (ProcessId.uintVal == pid)
            {
                *commandLine = QString::fromUtf16((ushort*)(long)CommandLine.bstrVal);// + sizeof(int)); //bstrs have their length as an integer.
                *executable = QString::fromUtf16((ushort*)(long)ExecutablePath.bstrVal);// + sizeof(int)); //bstrs have their length as an integer.

                qDebug() << *commandLine << *executable;
            }

            result->Release();
        }
    }

    // Release the resources
    EnumWbem->Release();
    WbemServices->Release();
    WbemLocator->Release();

    CoUninitialize();
    //getchar();

    return(0);
}

and in my Qt project file (.pro) I link to the following libraries:

LIBS += -lole32 -lwbemuuid
user_28954800
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