I might be wrong here, so correct me if I am. I think what the worm does is when you open your mail, it would automatically mails itself to other people on your contacts. Does no harm to your computer, actually. I think it is run on the server and thus affects both IE and firefox.
Quite correct. Although the worm does no harm to the local computer, it does take its toll on networks by clogging up bandwidth.What's scary is the fact that it's exploiting server-side JScript code to cause damage. All browsers are affected. This is NOT a browser issue, but an issue with Yahoo's implementation of scripting. Take note that this vulnerability does not exist for new BETA interface.