Special to CNET News.com Computer security experts fear a new worm that began spreading rapidly across Australian e-mail networks on Sunday could be a rehearsal for a more concerted attack in coming weeks. The worm--dubbed Bagle-A--carries an expiration date, possibly indicating that more robust versions of the worm could be slated for release soon, said Daniel Zatz, security director for Computer Associates Australia. While Bagle-A is already successful--responsible for an 80 percent increase in queries to CA's help desk and in virus submissions to rival computer security company Sophos--the current version of the worm contains bugs, Zatz said. Comparing Bagle...