X97M/Friend is a Excel 97 class infector.
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:Friend.A
When an infected workbook is opened, X97M/Friend.A disables Excel's built-in macro virus protection. Then it creates a workbook into Excel's startup directory, "sys.xls", and infects it. During infection the virus creates a temporary file, "C:\office.sys".
After that has been done and the Excel has been restarted, every workbook that is closed will be infected.
Variant:Friend.B
X97M/Friend.B is a slightly modified variant from X97M/Friend.A.