There is a worm (Zotob or a variant) that has been going around networks. It's all over the news because it's been hitting large corporations, including media, and notably affected CNN's broadcast schedule when it hit them.
If you use Windows, especially Windows XP or Windows 2000, I recommend that you download the patch immediately. If you have run Windows Update recently, you might already be protected, but you might want to download it anyway if you are not sure. Click here to get the fix for your Windows system
Also, as always, make sure your computer's antivirus program is up to date. If you have a PC and you don't have an antivirus program, GET ONE. There are free ones available that can be just as good as the ones you pay for at protecting your computer from viruses, worms, and malware.