Europe has been hit by a new, even more destructive variant of the Magistr virus, but so far the United States has baffled experts by remaining immune.
The Magistr.B virus arrives as an e-mail message and is contained in an executable file titled "readme.exe." Although it does not appear to have spread as widely as its predecessor, virus watchers say it could cause more damage to those who are infected.
The original Magistr.A worm remains active, with British e-mail screening service MessageLabs detecting 93,000 cases since March 14.
Magistr.B spreads via e-mail. It generates random subject lines and body texts, and attaches itself as a random file with a .bat, .bif, .exe, .pif or.com extension. Unlike the typical mass-mailing virus, the new variant can pull addresses from the files of several e-mail programs, including Outlook, Outlook Express, Eudora, Netscape Messenger and some Web-based e-mail programs.
Like the original worm, Magistr.B overwrites hard drives and erases system information stored by the BIOS (basic input/output system) chip, rendering the computer unusable. It adds the ability to infect Eudora address books and to disable ZoneAlarm personal firewall software before connecting to the Internet.