There is a "Help Center" link at the bottom of every page and, if you follow that, you'll find an option to Email customer support regarding and questions and concerns you have. Reporting potentially malicious downloads is one of the options provided.

However, I'm curious of two things:
1.) Did you click the Download Now button or the Direct Download link? The former downloads CNET's own downloader, which prompts you to install unrelated software and is flagged by some security software.
2.) What specifically did it report? (What was the name of the malware?)

Let us know.