Aug. 17, 2005 -- A software worm wreaked havoc for many Windows-based computer users and businesses on Tuesday, virtually crippling computer networks at media outlets such as ABC, CNN and The New York Times.
The malicious software code is believed to be a new worm called "Zotob." During the past week, Microsoft and computer security companies warned this new worm could allow an attacker to access PCs by exploiting a recently discovered flaw in Windows 2000.
Becky Worley, a tech expert and author of "Security Alert," joined "Good Morning America" with important information on the virus and what to do if your computer has been infected.
Why is this worm so potent?
It works without user intervention. The worm installs a program that scans through networks and IP addresses (every computer's "location" on the Internet) looking for vulnerable systems. There's no e-mail to open, no programs you choose to download, no Web sites that secretly install software -- it's all done automatically. And when worms and viruses propagate automatically, it happens fast, like the Code Red or Nimda worms in 2001.
How did Zotob slip by system security?
Zotob appeared on Sunday but was made public on Tuesday when Microsoft issued a patch.
Most IT managers don't automatically install patches because they can upset the delicate balance of software running on networks. They test the patches first and that can take some time. If IT managers installed every patch automatically as it was released, they could make their computer networks unstable.
The Zotob writer wrote an extremely effective program very quickly.
How does this worm affect computer users?
Anyone running Windows 2000 -- which is not a common operating system for home users -- is vulnerable to Zotob. Other operating systems can't be infected, but they can be used as carriers, relaying the software to other machines. Carrier machines will be besieged with traffic and requests, slowing them down to a crawl.
What should you do if you're infected?
If you can access the Web site, download the Zotob removal tool provided for free by Symantec. If not, download the removal tool on another computer, burn to a CD and install on the infected computer. Click Here for the Symantec site.
Go to www.windowsupdate.com and get the latest security patches for your Windows computer. Click Here for Windows Update.
Set up your computer to automatically update in the future by visiting the Microsoft security update site. Click Here to visit that site.
Make sure your anti-virus program is updated and running. If you don't have an anti-virus program, AVG from Grisoft is a free program that does the job. Click Here for Grisoft.
Install a firewall. Zone Alarm is a free product that works like a charm. Click Here for Zone Alarm.
Three Ways to Stay Virus-Free
Make sure automatic updates are turned on.
Run an anti-virus program and make sure it's updating automatically.
Install a firewall.