I was wondering the same thing. I was about to post and ask about it.
This from Panda's site.
http://www.pandasoftware.com/about/press/viewNews.aspx?noticia=6243"PandaLabs has recently reported the appearance of a type of malware that encrypts files on the infected computer and then asks for a fee in order to release these files. This is a new type of behavior, rarely seen until now, and to which the FBI in the United States are now alert.
The malware in question, Trj.PGPCoder.A, is a Trojan, and as is usual in these cases, cannot propagate by itself. Once installed on a computer, it creates two registry keys: one to ensure it is run on every system startup, and the second to monitor the progress of the Trojan in the infected computer, counting the number of files that have been analyzed by the malicious code."