This is a thread about 4.0, but the content is the same.
http://shoutbox.menthix.net/showthread.php?tid=89079
Basically, it's detecting something that will do no harm to you
As you can see in that thread,
AntiVir 7.9.0.168 2009.05.25 HEUR/HTML.Malware
AntiVir also detected it back then.
Nothing to worry about, Antirvir just fails