The virus, dubbed "I Love You," has already affected thousands of corporate sites, according to security firm Symantec, some of which were forced to shut down their email systems in an effort to choke it off.
A partial list of those affected by the virus confirmed by CNET News.com were Silicon Graphics, the Department of Defense, DaimlerChrysler, The Motion Picture Association of America, the Federal Reserve and Cox Cable.
The cost of lost business for such defensive actions alone could far outstrip costs attributed to previous attacks by viruses such as Melissa, which rang up a stinging $80 million price tag. Unlike Melissa, the I Love You virus has the ability to destroy data, which could drive potential costs considerably higher. The virus wipes out certain pictures and music files.
"In terms of spreadability, this will outrank everything we've seen so far," said Vincent Weafer, director of Symantec's AntiVirus Research Center (SARC). "Just based on initial reports of infections and potential infections, we're talking thousands of corporations around the world."
More than 45 million computers around the globe have been infected by various strains of the virus, according to Computer Economics, a research firm in Carlsbad, Calif.
"We estimate $2.61 billion of damage has been done," Samir Bhavnani, a research analyst with Computer Economics, told Reuters. "By Wednesday, the total can reach $10 billion. We see damages growing by $1 billion to $1.5 billion a day until the virus is eradicated."
Mike Wittig, chief technology officer
Analysts and victims of the virus say the parallels with Melissa extend largely to the mechanics of transmission and the silencing of some email systems. Beyond that, today's worm is leaving Melissa in the dust.
"This one is not that different from Melissa, and it spread outrageously fast," said Michael Zboray, chief technology officer for market researcher Gartner Group. As with Melissa, many companies' first response was to shut down email systems, paralyzing operations.
"In any kind of communications-intensive company, email is the de facto standard for communicating inside and outside the company," Zboray said.
Others agreed that I Love You has the ability to leave greater destruction in its wake than did earlier viruses.
"This is going to be expensive to clean up in two areas," said security consultant Richard Smith. "It's going to be a big mess for companies to clean up their mail servers, and that's going to be much like the Melissa cleanup. But there is also file deletion, so if you are a Webmaster with files on your hard drive, there's the possibility of lost work here."
Gartner Group estimates that in general, 40 percent of email messages coming into businesses have "dirty" attachments.
"Many of these are merely irritating but benign infections," Zboray said. "You literally have to view your business as an island that you are defending, because the outside world is dirty, and it's not going to (get) clean."