I came across this free video converter program for Windows called Any video converter and installed it, my antivirus program immediately found a virus within it (Win32:Evo-gen). How and where can I report that site distributes its program with a built-in virus?
After reporting the website in question to the relevant host (discovered by running a WHOIS as suggested by forest in their comment), you can also report the website to Google using their Report malicious software form. In the case of a phishing site the Report Phishing Page form should be used.
If your report is reviewed and accepted, the page will be excluded from Google's search results, and anyone using Google Chrome will get a warning page from Google's Safe Browsing and will be deterred from continuing. I believe that Chrome may also prevent the user from opening the executable downloaded from the website if the user ignores the big red warning page.