NEW YORK - The FBI launched a hunt Friday for the author of a new computer virus that is sneakier and more destructive than the ''Love Bug'' that infected millions of machines around the world two weeks ago.
The new virus, called ''NewLove,'' penetrated thousands of computers around the globe Thursday and Friday, causing them to crash.
But it didn't spread with the lightning speed of the Love Bug because many companies employed safeguards that had been put in place against the Love Bug.
''In this perspective, Love Bug was a very positive wake-up call,'' said Gene Hodges at the software company Network Associates Inc. in Santa Clara, Calif.
In Washington, the FBI opened an investigation.
The two viruses are similar, and both spread via e-mail. But the Love Bug was given away by the ''ILOVEYOU'' subject line of the e-mails that carried it, while NewLove changes subject lines every time it is sent.
''This makes the virus more difficult for users and anti-virus programs to detect,'' Attorney General Janet Reno said.
NewLove is also more destructive because it erases almost all files on a computer it infects and causes it to crash. The Love Bug targeted only a few files.
''Two weeks ago, we all got some love mail. Today we're getting hate mail. This is a very nasty one,'' said Simon Perry at software company Computer Associates International Inc. in Islandia.
Estimates of the damage caused by the Love Bug range up to $10 billion, mostly in lost work time. The NewLove virus is expected to total much less.
Hodges said a company in Israel was the first to report the virus, early Thursday. The company shut down its connection to the Internet to curtail the spread, but the virus later surfaced in Europe and the United States.
U.S. companies were quick to take protective measures, a marked difference from their reaction to the spread of the ''Love Bug.''
Hodges said network administrators calling two weeks ago said, ''Holy cow! I have 20,000 copies of this on my (e-mail server)! What do I do now?''
''This time, they were saying, 'I think I'm set. Is there anything more I need to do?''' he said.
The subject line of a NewLove e-mail starts with ''FW:'' and includes the name of a file from the sender's computer. The e-mail will have an attachment with the same name, but it may also have a ''.vbs.'' extension visible.
Clicking on the attachment will activate the virus. Like the Love Bug, NewLove will send itself to everybody in the user's address book. It will then overwrite most files on the hard drive, rendering the computer useless until the operating system is reinstalled.
As with the Love Bug, it will only spread from recipients running Microsoft's Outlook e-mail program.
Microsoft said it will release a modification to Outlook to eradicate the virus.
On the Net:
Network Associates' McAfee anti-virus unit: http://www.mcafeeb2b.com
Computer Associates: http://www.cai.com
Microsoft Office Update: http://officeupdate.microsoft.com
CERT Coordination Center: http://www.cert.org
National Infrastructure Protection Center at http://www.nipc.gov