[crarko adds: OK, there are some serious questions raised about the procedure described below. I suggest waiting for further corroboration before trusting it.]
Here is some background on the recent announcement about a piece of malware which has been found to affect Macs. The spyware in question is called OSX/OpinionSpy and it’s a new variant of Windows spyware that has existed since 2008.
This link (to The Guardian) offers a manual method to remove the spyware which was installed with the screen savers from 7art, or other infected applications which may have been installed.
To see if you're affected, run Activity Monitor (in /Applications/Utilities) and set it to show All Processes in the dropdown menu. Look for a process called 'PremierOpinion' which will be owned by root. If it's there, you've been affected.
To summarize the removal procedure:
Mac OS X Hints
http://hints.macworld.com/article.php?story=20100603055412831