Exe To C

Program-Transformation.Org: The Program Transformation Wiki

This is a decompiler for Win32 executable files, hosted on Windows. For a first release, it's quite good. It seems to have reasonable dataflow analysis, removal of unused statements, it recognises commonly used Windows functions and seems to get the parameters right, and emits most high level C statements such as if/switch/do/while. Here is a simple example from his own test program:

sub_401000  proc

     401000 PUSH   +04
     401002 PUSH   +03
     401004 PUSH   00408040
     401009 CALL   printf
     40100e ADD    ESP,+0C
     401011 RET
sub_401000  endp

which after a few clicks transforms into:

DWORD sub_401000 ()
    return printf ("hello %d and %d",3,4 );

It won't load certain Windows/PE programs, and occasionally fails, but it usually displays a message box before editing. Plus, of course, you can fix it yourself since source code is available.

After 100 steps, main transforms into:

DWORD main (bit32 a_4, bit32 a_10 )
    bit32 ESI ;
    bit32 EDI ;
    bit32 EBX ;
    bit32 EBP ;
    HACCEL ESI_2 ;
    bit32 EAX_5 ;
    tagMSG  v_1c ;

    sub_401020 () = sub_401020 ();
    Sleep (sub_401020 ());
    ESI_1 = a_4;
    LoadStringA (ESI_1,(UINT)0x67,"",(int)100 );
    LoadStringA (ESI_1,(UINT)0x6d,"",(int)100 );
    sub_401100 ();
    EAX_5  = sub_401190 ();
    if (EAX_5  == 0 )
        return EAX_5;
    ESI_2  = LoadAcceleratorsA (ESI_1,(LPCSTR)0x6d );
    if (GetMessageA (&v_1c.hwnd,(HWND)NULL,(UINT)0,(UINT)0 ) != 0 )
            if (TranslateAcceleratorA (v_1c.hwnd,ESI_2,&v_1c.hwnd ) == 0 )
                TranslateMessage (&v_1c.hwnd );
                DispatchMessageA (&v_1c.hwnd );
        while (GetMessageA (&v_1c.hwnd,(HWND)NULL,(UINT)0,(UINT)0 ) != 0 );
    return v_1c.wParam;

As you can see, variables are declared, there is type analysis, structures appear to be handled, parameters and returns are mostly handled. I analysed sub_401100, and it takes one parameter and returns a value (but the return value is not used). When I returned to main, however, I could not get it to recognise this. Even when I analyse sub_401100 first, it doesn't seem to use the information is has about the child procedure.

All in all, an excellent first release.

-- MikeVanEmmerik - 04 Aug 2005