Just in time for all your Christmas online gift buying, the Dasher.b virus loads a rootkit keylogger onto your computer to capture your credit card passwords. (If you have a Mac, you can stop reading now and relax.) From Brian Krebs:

[A] keylogger employed by viruses and worms usually works off a predefined list of financial and e-commerce sites. The keylogger program lies in wait until the victim visits one of those sites, at which time it intercepts any information entered into credit card and other personal data fields and transmits the information back to attackers.

Dasher.b is a more robust variation of Dasher.A which didn't propagate.