An Internet worm that uses Web search engines to find new victims spread widely on Monday, apparently causing problems for Google Inc. (search) on the day it set the price range for its initial public offering, Internet security experts reported.

The reports about the worm, a variant of a Web attack called MyDoom (search), came as outages on the search site Google.com hit in the United States, France and Great Britain. In many places the site was said to be working normally.

"The latest version of MyDoom, which started arriving in people's mail boxes in force today, uses search engines to find more recipients for its message," security research service SANS reported on Monday. "Some search engines report performance issues."

Web site performance slowed broadly on Monday, suggesting the possibility that a virus or other Internet attack may be causing problems, said Keynote Systems Inc. (KEYN), a Web performance tracking firm.

"It could be an indication that something is impacting the Internet overall. We are certainly looking into it and also looking into the possibility of some sort of attack. We are starting to see things creep up," said Keynote spokeswoman Della Lowe. "