Yahoo messaging worm installs bogus browser

May 22, 2006: Malware writers have created a new worm that installs a new browser and plays screeching music.

The trouble starts with a link apparently sent by a friend in Yahoo's instant messaging program.

Instant messaging security company FaceTime Communications Inc. described the malware, which it called yhoo32.explr, as "insidious" in a security advisory Friday.

When the link is clicked, a worm installs the so-called Safety Browser, a program that leads the user to pages mined with adware and viruses, FaceTime said. The Safety Browser uses an Internet Explorer logo to make it look more legitimate.

Malware spread through instant messaging programs is on the rise. However, FaceTime said this malware appeared to be the first to install a browser without the user's permission.

The bug also hijacks Internet Explorer's home page, directing users to the Safety Browser's Web site.

After it is launched, the worm sends itself to others on the user's instant messaging contact list.

The malware is engineered to overwrite instant messages typed by a user, FaceTime said. The infected message can also be changed on the fly, it noted.

The screeching music, however, is blocked by Microsoft Corp.'s Windows XP Service Pack 2, FaceTime said.

Trend Micro Internet Security products,

for home and office users, use in-the-cloud malware definitions that are updated every day, all day, as soon as new or altered strains of viruses and other malware are detected in the wild and analyzed. By offloading the bulk of these ever changing virus definitions to cloud servers, the load on your computers is greatly reduced. All users of Trend security programs are instantly protected from hostile web pages laden with malware exploits and hostile email, by the Trend Micro Smart Protection Network.