[Source] Dll Injector

.386
.model flat, stdcall  
option casemap :none 

include windows.inc
include kernel32.inc
include user32.inc
include Comctl32.inc
include shell32.inc
include gdi32.inc
include comdlg32.inc

includelib comdlg32.lib
includelib gdi32.lib
includelib kernel32.lib
includelib user32.lib
includelib Comctl32.lib
includelib shell32.lib

DlgProc			PROTO	:HWND,:UINT,:WPARAM,:LPARAM

.const

IDD_DIALOG1	equ 101
TamBuff     equ 256
TamResp     equ 512
icone       equ 150
;#########################################################################

.data?
hInstance		dd ?
hBitmap 		dd ?
lol     		dd ?
status  		dd ?
result  		dd ?
dlg         	dd ?
processid   	dd ?
prochandle  	dd ?
procaddress 	dd ?
handle      	dd ?
address     	dd ?
libsize     	dd ?
thread      	dd ?
statusinject    dd ?
hIcone		    dd ?
hList			dd ?
hListdll		dd ?
LB              dd ?
Processo PROCESSENTRY32 <>
ps PAINTSTRUCT <>
rect RECT <>

.data

img             db "asm.bmp",0
loled           db "Preencha os campos em branco Diretório da dll e o nome do Processo antes de clicar aqui!!!",0
titulo          db "Error...",0
injected        db "Dll Injetada com sucesso!!!",0
injectedt       db "DLL INJECTED!!!",0
injectederror   db "NOT INJECTED!!!",0
errorOP         db "ERROR in OpenProcess em Windows Vista e 7 execute como administrador",0
errorWP         db "ERROR in WriteProcessMemory em Windows Vista e 7 execute como administrador",0
ofn OPENFILENAME <>
StringFiltro    db "DLL",0,"*.dll",0 
                db "Todos (*.*)",0,"*.*",0,0
Buffer          db TamBuff dup(0)
BuffResp        db TamResp dup(0)
Processobuffer  db TamBuff dup(0)
Dllbuffer       db TamBuff dup(0)
Processbuffer   db TamBuff dup(0)
kernel32    	db "kernel32.dll",0
loadlib     	db "LoadLibraryA",0



.code

start:

	push 0
	call GetModuleHandle
	mov	 hInstance,eax
    call InitCommonControls
    push 0
    push offset DlgProc
    push 0
    push IDD_DIALOG1
    push hInstance
    call DialogBoxParam
	push 0
	call ExitProcess

;########################################################################
xzero_it proc lpmem:DWORD,cnt:DWORD

mov edi, lpmem
mov ecx, cnt     
shr ecx, 2      
cld
xor eax, eax 
rep stosd       
ret
xzero_it endp
inject proc
	
	begininjectt:
	push offset kernel32
    call GetModuleHandle
    
    mov handle,eax
    
    push offset Dllbuffer
    call lstrlen
    
    add eax,1
    mov libsize,eax
    push offset loadlib
    push handle
    call GetProcAddress
    
    mov procaddress,eax
    
    push processid
    push 0
    push PROCESS_ALL_ACCESS
    call OpenProcess
    
    mov prochandle,eax
    .if eax <1
    	mov statusinject,0
    	jmp errorinop
    .endif
    
    push PAGE_READWRITE
    push MEM_COMMIT
    push libsize
    push NULL
    push eax
    call VirtualAllocEx
    
    mov address,eax
    
    push NULL
    push libsize
    push offset Dllbuffer
    push eax 
    push prochandle
    call WriteProcessMemory
    
    .if eax <1
    	push MB_ICONERROR
    	push offset titulo
    	push offset errorWP
    	push 0
    	call MessageBox
    	mov statusinject,0
    	jmp errorinwpm
    .endif
    
    push NULL 
    push 0
    push address
    push procaddress
    push 0
    push NULL
    push prochandle
    call CreateRemoteThread

    mov thread,eax
    
    .if thread != 0
    	push offset injected
    	push 1009
    	push dlg
    	call SetDlgItemText
    	mov statusinject,1
    .elseif
    	push offset injectederror
    	push 1009
    	push dlg
    	call SetDlgItemText
    	mov statusinject,0
        jmp close
    .endif
    
    push INFINITE
    push offset thread
    call WaitForSingleObject
close:    
    push offset thread
    call CloseHandle

errorinwpm:    
    push MEM_RELEASE
    push libsize
    push offset address
    push prochandle
    call VirtualFreeEx
errorinop:
	cmp byte ptr ds:[statusinject],1
	jz errorinject    
	ret
	errorinject:
	inc [LB]
	push 1012
	push dlg
	call GetDlgItem
	mov [hListdll],eax

	push sizeof Dllbuffer
	push offset Dllbuffer
	call xzero_it

	push offset Dllbuffer
	push [LB]
	push LB_GETTEXT
	push [hListdll]
	call SendMessage
	
	push eax
	mov eax,DWORD ptr ds:[Dllbuffer]
	test eax,eax
	jnz begininject
	pop eax
	push 1008
	push dlg
	call GetDlgItem

	push 0
	push BST_UNCHECKED
	push BM_SETCHECK
	push eax
	call SendMessage
	ret
	begininject:
	pop eax

	push 1000
	call Sleep
	jmp begininjectt

inject endp
injetor proc lParam:DWORD
	
	.while status==1
	push   0
 	push   TH32CS_SNAPPROCESS
 	call   CreateToolhelp32Snapshot 
 	mov    [result],eax

 	mov    [Processo.dwSize],sizeof PROCESSENTRY32

 	push   offset Processo
 	push   eax
 	call   Process32First         
 	jmp    ProcessosRodando_Chk

ProcessosRodando_Loop:

	push 256
	push offset Processobuffer
	push 1004
	push dlg
	call GetDlgItemText
	.if eax!=0
	push offset Processo.szExeFile
	push offset Processobuffer
	call lstrcmpi
	.if eax==0
	push eax
	mov  eax, Processo.th32ProcessID
	mov  processid,eax
	pop  eax
	call inject
	cmp byte ptr ds:[statusinject],0
	jz forever
	jmp Error
	.endif
	.endif                                                                          

forever:	
 	push   offset Processo
 	push   [result]
 	call   Process32Next                   

ProcessosRodando_Chk:
 	test   eax,eax
 	jnz    ProcessosRodando_Loop      

 	push   [result]
 	call   CloseHandle   
	.endw
Error:
	push   [result]
 	call   CloseHandle
	push 0
	call ExitThread
	ret

injetor endp

Refresh proc

	push 1010
	push dlg
	call GetDlgItem
	mov [hList],eax

	push 0
	push 0
	push LB_RESETCONTENT
	push eax
	call SendMessage
	mov	[Processo.dwSize], sizeof Processo

	push 0
	push TH32CS_SNAPPROCESS
	call CreateToolhelp32Snapshot
	mov	[result], eax

	push offset Processo
	push eax
	call Process32First
	.while eax

		push offset Processo.szExeFile
		push 0
		push LB_ADDSTRING
		push [hList]
		call SendMessage

		push [Processo.th32ProcessID]
		push eax
		push LB_SETITEMDATA
		push [hList]
		call SendMessage

		push offset Processo
		push [result]
		call Process32Next
	.endw
	invoke	CloseHandle, [result]

	ret
Refresh endp

DlgProc proc hWin:HWND,uMsg:UINT,wParam:WPARAM,lParam:LPARAM
	LOCAL hdc:HDC
    LOCAL hMemDC:HDC
	mov		eax,uMsg
	mov     edx,hWin
	mov     dlg,edx
	.if eax == WM_NOTIFY

			push 0
			push 0
			push LB_GETCURSEL
			push [hList]
			call SendMessage

			push offset Processbuffer
			push eax
			push LB_GETTEXT
			push [hList]
			call SendMessage
			invoke  SetDlgItemText,dlg,1004,addr Processbuffer
			push offset Processbuffer
			push 1004
			push dlg
			call SetDlgItemText
			
	.elseif eax==WM_INITDIALOG
		push icone
		push hInstance
		call LoadIcon
		mov hIcone,eax
		push hIcone
		push ICON_BIG
		push WM_SETICON
		push hWin
		call SendMessage
	 	push LR_LOADFROMFILE
	 	push 100
	 	push 413
	 	push IMAGE_BITMAP
	 	push offset img
	 	push hInstance
	 	call LoadImage
        mov hBitmap,eax 
        push 1
        push 0
        push hWin
        call InvalidateRect
        call Refresh
     
	.elseif eax==WM_COMMAND
		mov edx,wParam
		shr edx,16
		
		.if dx==BN_CLICKED
		
			.if wParam==1008
			push 1001
			push hWin
			call GetDlgItem
			
			push 0
			push eax
			call EnableWindow
			mov status,1

			push 0
			push 1009
			push dlg
			call SetDlgItemText

			push 256
			push offset Processobuffer
			push 1004
			push dlg
			call GetDlgItemText
			or eax,eax 
			jz error

				push 1012
				push dlg
				call GetDlgItem
				mov hListdll,eax
				mov [LB],0

				push offset Dllbuffer
				push [LB]
				push LB_GETTEXT
				push [hListdll]
				call SendMessage
				mov eax,DWORD ptr ds:[Dllbuffer]
				test eax,eax
				jz error			
				
				push 0
				push 0
				push 0
				push offset injetor
				push 0
				push 0
				call CreateThread
				jmp endiff
				error:

				push MB_ICONERROR
				push offset titulo
				push offset loled
				push 0
				call MessageBox

				push 1008
				push dlg
				call GetDlgItem

				push 0
				push BST_UNCHECKED
				push BM_SETCHECK
				push eax
				call SendMessage
				endiff:
			.elseif wParam==1007

			push 1001
			push hWin
			call GetDlgItem

			push 1
			push eax
			call EnableWindow

			push 0
			push 1009
			push dlg
			call SetDlgItemText
			mov status,0
			.elseif wParam==1001

			push 0
			push 1009
			push dlg
			call SetDlgItemText
				.if status==0

				push 1012
				push dlg
				call GetDlgItem
				mov hListdll,eax
				mov [LB],0

				push offset Dllbuffer
				push [LB]
				push LB_GETTEXT
				push [hListdll]
				call SendMessage
				mov eax,DWORD ptr ds:[Dllbuffer]
				test eax,eax
				jz errorlol	

				push 256
				push offset Processobuffer
				push 1004
				push dlg
				call GetDlgItemText
				or eax,eax
				jz errorlol

				push 1010
				push dlg
				call GetDlgItem
				mov [hList],eax

				push 0
				push 0
				push LB_GETCURSEL
				push [hList]
				call SendMessage

				push 0
				push eax
				push LB_GETITEMDATA
				push [hList]
				call SendMessage
				mov [processid],eax
				call inject
				jmp pass
				errorlol:

				push MB_ICONERROR
				push offset titulo
				push offset loled
				push 0
				call MessageBox
				
				.endif
				pass:
			.elseif wParam==1011
         		call Refresh
         	.elseif wParam==1013
         	
         		push 1012
         		push dlg
         		call GetDlgItem

				push 0
				push 0
				push LB_RESETCONTENT
				push eax
				call SendMessage
					
			.elseif wParam==1006
			mov     ofn.lStructSize, SIZEOF ofn
         	push    hWin
         	pop     ofn.hWndOwner
         	push    hInstance
         	pop     ofn.hInstance
         	mov     ofn.lpstrFilter, OFFSET StringFiltro
         	mov     ofn.lpstrFile, OFFSET Buffer
         	mov     ofn.nMaxFile, TamBuff
         	mov     ofn.Flags, OFN_FILEMUSTEXIST or 
                 	OFN_PATHMUSTEXIST or OFN_LONGNAMES or
                 	OFN_EXPLORER or OFN_HIDEREADONLY
         	push offset ofn
         	call GetOpenFileName
 		 	.if eax == TRUE

			 push 0
			 push 1003
			 push hWin
			 call SetDlgItemText

			 push 1012
			 push dlg
			 call GetDlgItem
			 mov [hListdll],eax

			 push ofn.lpstrFile
			 push 0
			 push LB_ADDSTRING
			 push [hListdll]
			 call SendMessage
			 	
		    .endif
			.endif
		.endif	
		
	.elseif eax==WM_PAINT
		push offset ps
		push hWin
		call BeginPaint
        mov hdc,eax
        
        push hdc
        call CreateCompatibleDC
        mov hMemDC,eax
        
        push hBitmap
        push hMemDC
        call SelectObject
        
        push offset rect
        push hWin
        call GetClientRect

        push SRCCOPY
        push 0
        push 0
        push hMemDC
        push rect.bottom
        push rect.right
        push 0
        push 0
        push hdc
        call BitBlt
      
        push hMemDC
        call DeleteDC

        push offset ps
        push hWin
        call EndPaint
	.elseif eax==WM_CLOSE
		push 0
		push hWin 
		call EndDialog
	.else
		mov		eax,FALSE
		ret
	.endif
	mov		eax,TRUE
	ret

DlgProc endp

end start