Another worm alert.

Experts say an e-mail computer virus that lets hackers have remote control over infected machines is the most severe attack this year and it's continuing to spread.

The worm is known as W-32.Bugbear, or I-Worm-Tanatos. It infects computers that use Microsoft's Windows operating systems.

The virus has spread to dozens of countries since being discovered last week.

The worm replicates itself through a windows machine's e-mail address book. It can attach itself to previously sent e-mail messages and can spread through network systems, allowing hackers to intercept passwords and gain access to computers over the
Internet.

Once a machine is infected, a hacker could steal and delete information from it.

Some subject lines for the e-mail are “bad news,” “Membership Confirmation,” “Market Update Report,” and “Your Gift.”