This Tuesday, Microsoft announced a fix for a serious vulnerability in Microsoft Word for Mac. This Wednesday, according to a Symantec announcement, a Word file, created on a Mac, appeared that tried to exploit that vulnerability.

To prevent potential panic, it should be clearly stated that, although the file was created on a Mac, it seems to still target PCs running Windows. As far as anyone can tell, it does not infect Macs. And what it does on Windows machines is unclear as well. But both the timing and the unusual creation platform (the Mac) of this file are particularly interesting. Anyone running Windows on their Mac (for instance via Parallels or Boot Camp) should be particularly worried. And everyone should definitely stay tuned.