Over at TidBITS there’s a sensible article: A Real Mac OS X Trojan Horse Appears, describing how a reader of Macworld UK came across a file on the Gnutella file sharing network which purported to be a Web installer for Microsoft Word 2004. This reader downloaded it, noticed that the icon “looked genuine and trustworthy” and double-clicked it, only to discover that it had instead deleted his Home folder.
… this Trojan Horse merely preys on gullibility and cupidity to sucker people into launching (arguably, it’s a bit of digital Darwinism at work). It’s worth noting that this Trojan also doesn’t exploit any weaknesses in Mac OS X; it’s just a deceptively named program that deletes files, and there’s no foolproof way to prevent deceptively named malicious software on any platform. No anti-virus software is necessary to detect this Trojan, and it does not replicate itself. As long as you don’t download applications from untrustworthy sources, you have nothing to worry about, particularly if you maintain regular backups.
So, in case you’re confused, where do you get the new version of MS Word from? You’ll be paying a vendor. If there were somehow a free public demo or beta then you’d get that direct from Microsoft. Oh, and go back up your files now.