COMPUTER VIRUS LINKED TO E-MAIL : DOE OFFICIALS ISSUE WARNING ON PROGRAM ERASING USERS' HARD DRIVES.

Byline: Clint Swett Scripps-McClatchy Western Service

An e-mail warning that computer virus hunters had initially dismissed as a hoax may actually refer to a dangerous program that could wipe out a computer's memory in a matter of minutes.

Officials at the federal Department of Energy's virus hunting team Wednesday said they have discovered a program called AOL4FREE.COM that arrives attached to an e-mail message and if activated quickly erases a computer's C drive, the hard disk that generally holds most of a PC's data.

Apple Macintosh computers don't appear to be vulnerable to the program, said Bill Orvis, a member of the Energy Department's Computer Incident Advisory Capability team, headquartered at Lawrence Livermore Laboratories.

The program is technically not a virus because it doesn't spread beyond the computer that hosts it. Rather, it's of a class of programs called Trojan horses because it looks innocent but can do serious damage inside a PC.

Orvis said officials don't know the source of AOL4FREE.COM or how many computers it has affected.

``We've got a lot of messages about it, so at least some people must have been hit,'' Orvis said. ``When it finishes deleting all your files it prints an obscene message on your screen.''

The CIAC warning comes on the heels of a widespread e-mail message that incorrectly warns people that anyone receiving an e-mail message with the subject line AOL4FREE should not read the message because it will activate a virus that will wipe out the computer's hard drive.

Such an occurrence is technically impossible, Orvis said, because e-mail text can't carry a virus. But files sent along with e-mail messages as ``attachments'' can carry viruses or Trojan horses, and that's what AOL4FREE.COM appears to do.

America Online, the giant on-line computer service, has no connection with the Trojan horse other than that its initials are used in the program's title.

Tatiana Gau, who heads AOL's security system, said she was aware of the Trojan horse bearing her company's name and advised computer users never to launch a program that had come from an unfamiliar source.

AOL4FREE.COM apparently took its name from another program developed by computer hacker Nicholas Ryan in 1995 that gave hundreds of users free access to AOL's system.

Ryan, a Yale University computer science student, was sentenced in federal court last month to two years' probation, six months of home confinement and a fine for his actions.

Orvis of CIAC said the AOL4FREE.COM program can't do any damage unless the user executes it by double-clicking on the file icon. He suggests that anyone who finds such a program immediately delete it from the computer.

People who launch the program can limit the damage if they quickly hit control C on their keyboards. That may save some files and could allow others to be reconstructed using an undelete program, Orvis said.