X97M/Friend is a Excel 97 class infector.
Depending on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the suspect file, or ask you for a desired action.
More information on the scanning and removal options available in your F-Secure product can be found in the Help Center.
You may also refer to the Knowledge Base on the F-Secure Community site for more information.
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.
X97M/Friend.B is a slightly modified variant from X97M/Friend.A.