One can't code a virus in HTML
It is possible to create a link within a web page to a virus or other malware and have it download and execute automatically IF no firewall or anti-malware detects and defeats it, which is unlikely if firewall and anti-virus software is up to date.
If a virus were actually able to reside inside an ordinary HTML web page, it would be visible by listing the page source code - but you can't code a virus in HTML - only link to one.
Oh to be free, so blissfully free, of the ravages of intelligence, there is no greater joy! - The Cweationist's Cweed
All that is necessary for evil to triumph is a good PR firm.
Very funny, Scotty. Now beam down my clothes!