Techie flu

August is the cruelest month for personal computers. Sensational viruses with names like SoBig, LoveSan, and Welchia scour the Internet looking for victims to infect. It means extra business for security and support firms, but mass annoyance for countless others.

One version of SoBig may be the fastest-spreading virus in history. MessageLabs, a British e-mail security firm, announced it intercepted 1 million copies of SoBig.F in just 24 hours. One in 17 e-mails headed through the Net were infected.

SoBig.F spams the globe with e-mails with the message: "Please see the attached file for details." Those who accept the invitation spread the virus, overwhelming inboxes and servers with multiple e-mail messages.

Like the Klez virus, another inbox horror, SoBig.F uses a built-in mail server to send bulk messages. The "from" headers are forged with real e-mail addresses, so that the messages appear to come from innocent people.

Preventing infection from bugs like this requires following now-standard advice: Back up valuable documents. Don't open e-mail attachments. Use anti-virus software and keep it updated. Get a firewall-the Internet's answer to the deadbolt lock-if you have a fast connection. Install all the latest security patches for your operating system.

SoBig.F's onslaught will be short-lived. The virus is set to self-destruct on Sept. 10, when a preprogrammed expiration date kicks in and stops its spread.

This bulk-mailed nightmare follows the spread of LoveSan, which does not even need tainted e-mail to attack PCs. The worm looks for open doors through Internet connections.

Microsoft may suffer the biggest embarrassment from all this-even though it issued a patch in mid-July that stops LoveSan. Chairman Bill Gates announced a "Trustworthy Computing" policy in early 2002 that demanded more secure programs. Hackers openly mock this crusade, which may have encouraged virus writers to humiliate the software giant.