Summary

W97M/Mimir.A is an overwriting Word 97 macro virus with a mass mailing ability.

Additional Details

When an infected document is opened, the virus will change the title of the Word's window to:

MiMiR is giving your computer new intelligence!
Then the virus ovewrites the three recently used documents as well as every file with ".doc" extension in the "C:" drive with the active document.

Finally it attempts to use Outlook to send a message to the every person listed in the "Contacts" folder. The body of these messages contains the following text:

Some nice jokes you got to read!! :))
The active document is attached to the message as well.

[Analysis: Sami Rautiainen, F-Secure]