Sasser Worm Rips Through Internet

The rapidly evolving “Sasser” computer worm tore across the Internet on Tuesday, claiming new victims among corporate and home computer users as others scrambled to fortify their machines against attack.

First detected over the weekend, the worm has already infected, by some estimates, more than 1 million PCs running on Microsoft Corp.’s Windows 2000, NT and XP operating systems.

Sasser infects vulnerable PCs without any action by the user and thus can spread quickly. In the last three days, four variants have emerged, each capable of causing machines to reboot without warning.