A damaging new computer worm was spreading like wildfire across the Internet this morning, hitting both home users and business in an outbreak that could prove more widespread and costly than the Code Red viruses, computer security experts say.
Known as Nimda , which spells admin backward, the virulent software worm first appeared in the United States on Tuesday and was spreading rapidly in Asia, with infections reported in Japan, Hong Kong, Taiwan, South Korea, Singapore, and China.
The mass-mailing worm arrives in e-mail messages without a subject line and containing an attachment titled readme.exe that is disguised as a harmless audio file. It also inserts itself into the makeup of Web pages and can spread when users download files onto their computers.
Nimda does not appear capable of erasing files or data but has shown itself capable of slowing down computer operations as it replicates, experts said.
The worm has not significantly slowed overall traffic on the Internet, although some corporate and government networks were bogged down.
Japan's Ministry of Agriculture said its network was hit and that it had tackled the virus, but it warned people to be careful of e-mail sent directly from the ministry.
Numerous corporate Web sites were also infected, including that of Microsoft Corp's Japanese unit.