Anti-virus software maker Symantec has put out an advisory about a new macro virus for Microsoft Word, which, in a worst-case scenario, can overwrite the master boot record of any and all drives on a computer.
The virus, named W97M.Killboot, infects a currently active document and the Normal.dot template when an infected document is closed. Once this template is infected, clean documents will be infected when they are closed.
It creates the file C:\Setver.exe, which the Symantec antivirus products detect as Trojan.Killboot. If Trojan.Killboot is run, it writes the viral code into the Master Boot Record; this can overwrite the MBR on all physical hard drives with zeroes.
Source
DualBootPRO