WM97/Marker-A is a Word macro virus. The virus keeps a log of user addresses and machines names as comments at the bottom of the macro, which is updated on each new infection.
Many variants of WM97/Marker-A have a payload similar to WM97/Marker-C. As well as logging infections at the bottom of the macro, they FTP the user information to the Codebreakers hacking website.
Some variants of WM97/Marker-A do not FTP the information but instead have a payload similar to WM97/Ethan.