Hark is a simple Word Macro virus. Infected documents have macros called "AutoOpen" and "Harkone".
This virus has an interesting activation routine. On 1st of June the virus maximizes all active windows, changes the font size to 60 and insert the test "HARKONE" and "NJ [SLAM]".
SLAM is a name of a virus-writing group.
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.