We updated the Mydoom virus page today with information about Mydoom.C (a.k.a. DoomJuice.A) You can get the details here.
We also updated the MyDoom (A,B) and DoomJuice.A Worm Removal Tool. Here's some information about that:
This tool will help to remove the MyDoom.A, MyDoom.B, and DoomJuice.A (aka "MyDoom.C") worms from infected systems. Once the tool has run—after the End-User License Agreement (EULA) is accepted—it automatically checks for infection and removes any of the targeted worms that are found. If a machine is infected with the MyDoom.B worm, the tool will also provide the user with the default version of the hosts file and set the "read-only" attribute for that file. This action will allow the user to visit previously-blocked Microsoft and antivirus websites.