The Beagle (or Bagle) worm has been unleashed, and it's spreading across the Internet quickly.

Though it won't necessarily damage your PC, it will pilfer your hard drive for email addresses, potentially harvesting them for spammers bent on selling the data to other email marketers.

Tonight on "Tech Live," we'll bring you the very latest on Beagle (aka Bagle), and tell you how to get rid of the worm if it claws its way into your machine.

As always, don't open attachments

Beagle, officially W32.Beagle.A@mm, began appearing en masse over the weekend, and has earned itself "high" rankings on Symantec's security response wild and distribution threat metrics.

The worm arrives looking like a test email from a system administrator, and includes an attachment with any number of random names.

Graham Cluley, senior technology consultant for Sophos, said in a statement: "The worm pretends to be a 'techie-looking' test email to fool people into running the dangerous attachment -- not knowing they are potentially giving hackers the power to run destructive code on their computer."

When the email is executed, it scans the system for files with the extensions .wab, .txt, .htm, and .html. It looks for email addresses within these files, then emails itself to the addresses. The worm won't send itself to addresses with the following domain names: @.r1, @hotmail.com, @msn.com, @microsoft.com, @avp.com.

A nuisance, but no PC killer

Other than replicating itself and infecting others, Beagle does not run an immediately damaging script. The worm does install a backdoor program listening for activity on port 6777. This backdoor could allow the remote attacker to execute commands on the infected system, download executable programs, or delete the Beagle worm program entirely.

Beagle's relatively high threat-rating stems from its extensive distribution in such a short amount of time. Computer Associates says Beagle/Bagle accounts for an 80 percent increase in its normal virus submissions in the last two days.

Whoever released the worm used a classic trick: It was released over a weekend that was, for many Americans, a three-day break. This is done thinking that network administrators won't be at work for three days, and won't detect the presence of a new worm on their systems. Beagle has now spread around the world, according to antivirus specialists.

Stonger attack coming?

Beagle is set to expire Jan. 28, which might seem like a positive sign. But some members of the antivirus community anticipate a more powerful variant of Beagle released toward the end of the month. Many are drawing parallels between Beagle and the Sobig worm that also spawned progressive variants growing in their destructive capabilities.

Users who think they may have been infected should look for a file called bbeagle.exe in the Windows System directory. It tries to disguise itself with the Microsoft calculator icon.

If infected, PC users should run Symantec's free removal tool.