Microsoft Office 2010 Technical Preview should be available in July 2009 (we are still working on it). But, there are some non-official copies that are already floating around on the Torrents.
Quite a few are infected with malware. The same thing happened to unofficial Windows 7 copies, resulting in a Botnet of compromised machines.
If you did not download Microsoft software directly from Microsoft, then don’t use it, you don’t know who did what to it. If you install those unofficial copies from untrusted sources, you are exposing yourself and your data and your network.