Netsky.y Sparks High Threat Level

Netsky.y arrived in the wake of Netsky.x, which also appeared Tuesday. Version Y is classified as a "high" threat level by security firm Panda Software, Glendale, Calif.

Like other worms in the Netsky family, Netsky.y attacks via e-mail using a spoofed address. The e-mail displays a subject line which reads "delivery failure notice" along with an 8-digit "ID" number, according to Panda.

The worm is unleashed when the e-mail recipient opens the attached file.

As soon as it infects a computer, Netsky.y e-mails itself to contacts it locates in the address book of programs such as Microsoft Outlook or MSN Messenger. It also searches for e-mail addresses in files carrying certain extensions such as WAB, HTM, HTML, TXT, according to Panda.

Netsky.y ultimately launches denial-of-service attacks (DOS) against several sites, including www.nibis.de, www.medinfo.ufl.edu and www.educa.ch.