By Robert McMillan

Wed, May 20, 2009 — IDG News Service — The Conficker worm is still infecting systems at a brisk rate and continues to snag computers in Fortune 1000 companies, according to security researchers.

The worm is infecting about 50,000 new PCs each day, according to researchers at Symantec, who reported Wednesday that the U.S., Brazil and India have been hit the hardest.. "Much of the media hype seems to have died down around Conficker/Downadup, but it is still out there spreading far and wide," Symantec said in a blog post.

Conficker began spreading late last year, taking advantage of a recently patched flaw in Microsoft's Windows operating system to infect entire networks and also using removable storage devices to hop from PC to PC. Security experts say it has now infected millions of computers worldwide, which now comprise the world's biggest botnet network.

"We can see that companies that spend literally millions of dollars on equipment and gear to prevent infections … these Fortune companies have had this infection and it's stayed in their networks for a long period of time," said Rick Wesson, CEO of Support Intelligence and a member of the Conficker Working Group. "It's really hard and really expensive, and if the Fortune companies can't stop it, how can you expect small businesses to do it?"

Continued @ CIO.com