Yahoo IM Worm Hijacks Browsers

A worm running through Yahoo's instant messaging network is installing a browser of its own -- a first for IM malware -- that leads users to adware and spyware sites, several security firms said Monday.

The worm, dubbed Yhoo32.explr by IM security vendor FaceTime Communications on Friday and Browaf by Symantec on Monday, is installed when Yahoo users click on a malicious link embedded within an instant message.

Yhoo32.explr downloads and installed the so-called Safety Browser, which adds an IE-like icon to the desktop, and when used, takes the unsuspecting to sites where their PCs are infected with adware and spyware. The worm also changes the home page of IE to point to Safety Browser's site.

To complicate things, Safety Browser doesn't post an Uninstall option in Windows' Add or Remove Programs Control Panel applet.