W32.HLLW.Qaz.B is a minor variant of W32.HLLW.Qaz.A. There is no difference between these two variants in terms of execution routines and side effects.
Configure Windows for maximum protection
Because this virus spreads by using shared folders on networked computers, to ensure that the virus does not reinfect the computer after it has been removed, Symantec suggests sharing with read-only access or using password protection. For instructions on how to do this, see your Windows documentation or the document How to configure shared Windows folders for maximum network protection
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