Threat Description



Category: Malware
Type: Virus
Platform: W97M
Aliases: FF


W97M/FF is a simple Word class infector.


Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.

More scanning & removal options

More information on scanning or removal options is available in the documentation for your F-Secure security product on the Downloads section of our Home - Global site.

You may also refer to the Knowledge Base on the F-Secure Community site for more information.

Contact Support

For further assistance, F-Secure customers can request support online via the Request support or the Chat forms on our Home - Global site.

Technical Details


When an infected document is opened, W97M/FF.A deletes the "Tools/Macros" menu and disables the built-in macro virus protection first. Then the virus creates a temporary file, "C:\FF.sys", and infects the global template.

Afterwards every opened document is infected.

the virus activates its payload on the first day of every month. It alters the "c:\msdos.sys" file by changing the


line to


This causes Windows 95/98 to start in command line mode after boot, instead of graphical user interface (GUI).


This variant is functionally identical with W97M/FF.A.

Technical Details:Sami Rautiainen, F-Secure


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