A new computer virus, first detected on Thursday, is already making its way around the globe, infecting computers at major corporations and government agencies as well as home users.
The virus has been dubbed "Here you have," based on the subject line in the emails spreading it.
Symantic Security Response, the viral tracking branch of Symantic antivirus products, lists "Here you have" as a malicious computer worm using a socially engineered email attack.
The virus arrives in an email that directs the recipient to click on a link that appears to be a PDF file but is actually the malicious program.
Once it's been clicked, the file downloads a program that disables many common antiviral programs, then emails a copy of the original message to everyone on the computer's address book.
If it's downloaded to a business computer using a shared network, the virus will jump from computer to computer, infecting the entire system.
There are reports that computer networks at NASA, Disney and Wells Fargo have been infected, along with the Kansas Department of Transportation.
What is most surprising about the viral attack is its similarity to the Anna Kournikova virus, which infected computers around the world in 2001.
Security experts say computer users should have learned by now that clicking on an email attachment is dangerous, even if you recognize the sender.