Symantec Security Response has developed a removal Tool to clean infections of W32.Welchia.Worm, W32.Welchia.B.Worm, W32.Welchia.C.Worm, and W32.Welchia.D.Worm. The W32.Welchia.Worm Removal Tool does the following:
Terminates the W32.Welchia.Worm (or W32.Welchia.B / W32.Welchia.C / W32.Welchia.D) Worm viral processes. Deletes the files that the worm added. Deletes the registry values that the worm added.
Note: Deletion will be performed only if the operating system has not already removed these values upon terminating the viral processes, as mentioned in step 1.