A quick note, it is important to be more paranoid of all attachments and links to web sites. This one is a authentic, serious risk of permanently losing work or home files. Notice that it scans for files on network shares as well.
In addition to paranoia, I recommend downloading and installing this program with the default settings. I have done this on my work laptop and on my home computer.
Read as much as you want about this nasty extortion process:
--New Hampshire Town Lost Files to CryptoLocker
(January 7, 2014)
A New Hampshire town has lost eight years worth of computer files to the CryptoLocker ransomware. An employee at the Greenland, NH, town hall opened an attachment accompanying an email purporting to be from AT&T on December 26. The system administrator did not learn about the issue until four days later, after the deadline for paying the ransom had expired.