The virus scan message comes not from Word but from linked anti-virus
software. Checking of Word/Office documents can usually be deselected in the
AV program e.g. in Norton AV by turning off its Office Plug-in.

With some versions of the Norton product it may be necessary to unregister
the calling DLL by running the following command line from Windows > Start >
Run

regsvr32 /u "c:\program files\norton antivirus\officeav.dll"
or
regsvr32 /u "c:\program files\norton systemworks\norton
antivirus\officeav.dll"

Other AV apps eg the popular free ediition of Grisoft's AVG antivirus
software, require similar treatment.
In this instance:

regsvr32 /u "C:\Program Files\Grisoft\AVG Free\avgoff2k.dll"