Jeanne Smythe, director of computing policy at Academic Technology & Networks, said the worm, called Nimda, is carrying out a denial of service attack that uses up most of the network bandwidth.
Starting at 9:45 a.m. Tuesday, Nimda invaded more than 40 campus computers through Microsoft Internet Explorer, Microsoft Outlook and Microsoft Outlook Express, Smythe said. As the worm used up network bandwidth trying to spread to other computers, many network services became inaccessible.
"A denial of service attack means that so many computer resources are used that other work can't get done," Smythe said.
UNC officials began working to resolve the problem by protecting the network from the infected computers as soon as they were discovered. "I know we certainly responded quickly on campus to isolate any problems," Smythe said. "Any that we have discovered we have isolated and put in the penalty box."
But Nimda still can resurface because it continues to attack computers off campus and can be transmitted via Web sites or e-mails. "If (students) are using Internet Explorer, Outlook or Outlook Express, they have to be careful," Smythe said.
She added students should take precautions to protect their computers from the worm. In Internet Explorer, students should disable file downloads and JavaScript applications, and in Outlook, students should disable autopreview and not open any unexpected e-mail attachments.
Additionally, Microsoft Windows can be updated to include the latest antivirus programs by choosing the Windows Update icon from the Start menu.
Besides slowing down the network, Nimda also damages the individual computers it infects. Smythe said the worm has the ability to delete and replace some files saved on the computer.
While the worm affected some students, others barely noticed it. But the inability of professors to access the Internet during class was one of students' major complaints.