This is a simple Word 97 macro virus.
Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.
A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:
Check for the latest database updates
First check if your F-Secure security program is using the latest updates, then try scanning the file again.
Submit a sample
After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.
Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.
Exclude a file from further scanning
If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.
Note: You need administrative rights to change the settings.
Variant:Nsi.A
This variant disables the built-in macro virus protection and replicates during opening and closing. The virus contains the following commented line on the bottom of its code:
'ThisDocument v 1.0 1999 W97M/Nsi.B
W97M/Nsi.B is functionally like W97M/Nsi.A. The commented line in W97M/Nsi.B is:
'Psycode v1.0 1999