Finding base address in a remote process

[taos]

Originally Posted by yaa

I was wondering how I can retrieve the base address of an external process. My need it to get to its IAT and I suppose the base address could be a good starting point but ... I was not able to find any useful piece of code around.

//
// Gets the address of the entry point routine given a
// handle to a process and its primary thread.
//
DWORD GetProcessEntryPointAddress( HANDLE hProcess, HANDLE hThread )
{
    CONTEXT             context;
    LDT_ENTRY           entry;
    TEB                 teb;
    PEB                 peb;
    DWORD               read;
    DWORD               dwFSBase;
    DWORD               dwImageBase, dwOffset;
    DWORD               dwOptHeaderOffset;
    optional_header     opt;
    
    //
    // get the current thread context
    //
    context.ContextFlags = CONTEXT_FULL | CONTEXT_DEBUG_REGISTERS;
    GetThreadContext( hThread, &context );
    
    //
    // use the segment register value to get a pointer to
    // the TEB
    //
    GetThreadSelectorEntry( hThread, context.SegFs, &entry );
    dwFSBase = ( entry.HighWord.Bits.BaseHi << 24 ) |
                     ( entry.HighWord.Bits.BaseMid << 16 ) |
                     ( entry.BaseLow );
    
    //
    // read the teb
    //
    ReadProcessMemory( hProcess, (LPCVOID)dwFSBase,
                       &teb, sizeof( TEB ), &read );
    
    //
    // read the peb from the location pointed at by the teb
    //
    ReadProcessMemory( hProcess, (LPCVOID)teb.Peb,
                       &peb, sizeof( PEB ), &read );
    
    //
    // figure out where the entry point is located;
    //
    dwImageBase = (DWORD)peb.ImageBaseAddress;
    ReadProcessMemory( hProcess, (LPCVOID)( dwImageBase + 0x3c ),
                       &dwOffset, sizeof( DWORD ), &read );
    
    dwOptHeaderOffset = ( dwImageBase + dwOffset + 4 + sizeof( coff_header ) );
    ReadProcessMemory( hProcess, (LPCVOID)dwOptHeaderOffset,
                       &opt, sizeof( optional_header ), &read );
    
    return ( dwImageBase + opt.entry_point );
}

More usefull information
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