For the third consecutive week, e-mail viruses took their toll on campus computer networks.
During the first week of school, the Gabot worm saturated the campus network with traffic, preventing students from accessing the InfoNet course registration system. Last week, various worms including Swen, which infected millions of computers world-wide, also devastated vulnerable computers at the University of Calgary.
"Unpatched machines are a risk to all others and the entire U of C network in general," wrote Network Services Manager Tom Seto on Fri., Sept. 19. "We do not want a repeat of Sept. 8 and 9 so we have started taking a proactive approach."
At the end of last week, over 400 computers remained vulnerable due to bugs in the Microsoft Windows operating system. Network operators blocked certain kinds of network access to prevent the spread of the worms, and disconnected unpatched and infected computers over the weekend to prevent further infections this weekend.
In attempting to patch their systems to correct the bugs, some users fell victim to the Swen worm, which spreads via e-mail, file-sharing applications such as KaZaa, and mapped network drives, masquerading as an official patch from Microsoft. Microsoft does not normally send patches to users via e-mail.
"We have implemented a policy to scan and cut off unpatched systems on an ongoing basis," wrote Seto. "Having an up-to-date patched system is a condition for network access."
Students, faculty and staff can obtain free tools to remove current worms and viruses from their computers, as well as antivirus software and updates at www.ucalgary.ca/it/virus.