Description
This is a virus detection. Viruses are programs that self-replicate recursively, meaning that infected systems spread the virus to other systems, which then propagate the virus further. While many viruses contain a destructive payload, it's quite common for viruses to do nothing more than spread from one system to another.
Indication of Infection
The above registry changes if day is 1st, 14th or 28th of the month. The presence of the file maike.sys in the windows SYSTEM directory.
Methods of Infection
Opening infected documents will directly infect the local Word environment and any document used thereafter.
Aliases
W97M.Maike (NAV), WM97/Ekiam-A (Sophos)