about WS.Viral1;

http://www.symantec.com/security_response/writeup.jsp?docid=2010-052608-1836-99

It's an 'undefined' detection meaning there is no specific threat but the file, perhaps, displays properties that may be considered as suspicious.

The reason is you are using CNET's new installer process which has been introduced to make downloads more secure. But in that process CNET offers the user the option of downloading a 3rd party tool or toolbar. This helps CNET generate revenue. It is this that Norton is detecting. The 3rd party software is, itself, malware free, but Norton detects it as a possible hijack.

In such cases we always recommend users opt for the "Direct Download" link instead of the CNET_Installer link.

I hope that helps.

Mark