W97M/Myna is a simple Word 97 macro virus.
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.
W97M/Myna.C infects the global template when an infected document is opened or created.
The virus uses a string "MYNAMEISVIRUS" as an infection marker, thus the name.
It does not do anything else but replication.