2 replies to this topic

[JMC31337]

Demontration of how to call MessageBoxA.
1 way is through predefined text in the .Data
the other is through command line...
i found the GetCommandLineA from a Phrack exploit code
many thnx to them.... :)
NEW.ASM

.386P   
Locals
jumps 
.Model Flat ,StdCall
include windows.inc
mb_ok     equ 0             
hWnd      equ 0   
lpText    equ offset Text
lpCaption equ offset caption
lpBlnk    equ offset Blnk
extrn     ExitProcess      : PROC
extrn     MessageBoxA      : PROC
extern    GetCommandLineA  :proc
.Data                                        
text     db "Hello_World",13,10,0
caption  db "",0 
Blnk     db "",0
.Code                                  
Main:
        call OPEN_PROGRAM 
        push mb_ok              
        push lpCaption          
        push lpText             
        push hWnd               
        call MessageBoxA        
        call ExitProcess        
 
OPEN_PROGRAM   PROC
      ARG    szP:DWORD
      call   GetCommandLineA 
      mov    szP,eax
      add    szP,4               ;add bytes to remove the new from msgbox
      PUSH   MB_OK
      push   lpBlnk
      PUSH   szP
      push   hWnd
      CALL   MessageBoxA
      ret
OPEN_PROGRAM   ENDP
End Main

compile with
tasm32 /mx /m3 /z /q new
tlink32 -x /Tpe /aa /c new,new,, import32.lib
if you want a dll then change /Tpe to /Tpd and also change
add szP,4 -> add szP,16
rename the file change the add szP according to filename_length

use rundll32 new.dll MESSAGE! for DLL example

[dargueta]

This should be in the Tutorials forum; there's a subsection there for ASM tutorials. Good intro, though. :)