Due to a decreased rate of submissions, Symantec Security Response has downgraded the threat level of this worm from Category 3 to Category 2.
W32.HLLW.Bymer is a worm written in a high-level language. The worm spreads over shared network drives. It searches for shared folders on the network and then copies itself to the \Windows\System folder.
The payload copies the Dnetc client
and modifies the Win.ini file. The Dnetc client is not viral and is not detected by Norton AntiVirus.
The worm was previously detected as Dnet.Dropper.
Symantec has created an interactive tutorial
to help you remove this worm.
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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