Latest Worm Infects 9 Million PCs

The Worst Outbreak in Years

Using a flaw in the Windows Server service that was detected and patched months ago, a single worm has managed to infect nearly 9 million PCs in just over two weeks — and the rate of infection is increasing by the day. In just four days, the "Downadup" worm (which is also sometimes referred to as "Conficker,") spread from an estimated 2.4 million computers to 8.9 million. It has been described by many security experts as the worst outbreak of malicious software in years.

In October, Microsoft sent out a rare emergency security update for all of its operating systems, including Vista, XP, and Windows 2000. Unfortunately, this update seems to have been ignored by a large portion of PC users, leaving millions vulnerable to Downadup.

Full Dangers Still Unknown

Right now the intentions of developers responsible for the malicious software remains unclear. For the time being, the hackers have only bothered to send out a fake security security program, which creates pop-ups designed to annoy users into paying for a worthless program. But Downadup could potentially hijack millions of computers and use them as bots capable of carrying out whatever commands the hackers send them.

That the whole problem could have been averted if users had just bothered installing a patch Microsoft issued long ago, underscores the importance of setting your operating system to automatically download and install security updates. Those with infected computers undoubtedly let the patch languish for months in an update queue, alongside much less essential software updates.

How to Update Windows Automatically

Windows XP

To set your PC to update automatically in Windows XP, simply access the Control Panel in the start menu, click "Automatic Updates," and choose "Automatic."

Windows Vista

For Vista, open Windows Update in the start menu, select "Change Settings," and then select "Install updates automatically."

How to Remove the Worm

Your computer might not be showing any signs of infection or you may have seen some odd behavior.

From Microsoft:

If your computer is infected with this worm, you may not experience any symptoms, or you may experience any of the following symptoms:

• Account lockout policies are being tripped.

• Automatic Updates, Background Intelligent Transfer Service (BITS), Windows Defender, and Error Reporting Services are disabled.
• Domain controllers respond slowly to client requests.
• The network is congested.
• Various security-related Web sites cannot be accessed.

If your PC has already been infected by Downadup, first install the emergency update, then run the latest edition of Microsoft's Malicious Software Removal Tool to remove the worm from your computer.

More information about the worm is available from Microsoft. You can also read more on Computerworld.