A computer virus known as "Klez," a mass-mailing e-mail worm, has been causing problems for Penn State students and faculty since February.

According to an alert posted on the Center for Academic Computing's Web site (http://cac.psu.edu), the worm, designated "W32.Klez.E@mm" affects Microsoft Windows users who use the Microsoft Outlook or Outlook Express e-mail programs. When an infected e-mail message is opened or even previewed, the virus executes because of a security flaw in the e-mail programs.

"It sends itself out to anyone in your address book," David Drager (senior-telecommunications), a ResCom employee, said.

Infected machines send e-mails to the addresses it locates, using random subject lines, message text and attachment file names such as .bat, .exe, .pif, or .scr.

"This e-mail virus is particularly insidious," Kathleen Kimball, director of Computer and Network Security, said.

Of particular concern to some is the fact that the worm has a payload, and will overwrite files on the hard drive with the extensions .txt, .html, .doc, .mp3, .htm, .wab, .cpp, .c, .pas, .mpg, .mpeg, or .bak., on the 6th day of every odd numbered month except January or July, according to Symantec's Web site (www.symantec.com).

If the month is January or July, this payload tries overwrite all files on the hard drive.

The worm's payload will also attempt to disable any common anti-virus software that might be on a user's hard drive, such as Norton AntiVirus or McAfee VirusScan.

Symantec makes the virus protection program Norton AntiVirus.

CAC's Web site offers some tips for students to prevent their computers from becoming infected with a virus or worm.

First, they said to install the most current virus protection software available.

"Students can get Norton AntiVirus in the basement of Willard for free, or download it," Drager said.

The software is available at https://downloadsym.cac.psu.edu.

He said using virus protection software is the best way for students to protect their computers from any problems, and he said it is important to update the virus software on a regular basis.

CAC also suggests that students back up their files on a regular basis and advises computer owners to stay informed on virus news and vulnerability issues.

If a student thinks they might have the virus, CAC said to scan all files using virus protection software. If Norton VirusScan detects the virus, it will prompt the user to delete the infected files.

"Network Security will shut down a student's ability to send e-mails if they detect you have a virus and have been sending out infected e-mails," Drager said.

If the virus is already on a computer, "Klez" might not allow the user to install virus protection programs. CAC advises students to contact the help desk at 863-1035 in this situation.

For more information on the "Klez" virus, visit the Symantec Web page at www.symantec.com/avcenter/venc/data/pf/ w32.klez.e@mm.html.