"We have only received one submission from the field, but the technical aspects of this are concerning. It has all the components there to become a significant virus." - Craig Schmugar, senior virus research manager at McAfee.
And while we are on the subject of viruses, there is a MyDoom which draws on IE flaws to spread. Labelled MyDoom.AG by McAfee and MyDoom.AH by Symantec, the nasty little blighter uses a recently discovered vulnerability in the browser software allows the offshoot to infect a PC after a user clicks on a link.