Computer virus hinders Air Canada operations

TORONTO -- A computer virus designed to inoculate against another infection brought down some computer networks Tuesday, forcing Air Canada to check in passengers manually at airports across the country.

Long lines formed at counters at Vancouver International Airport as the virus slowed Air Canada's computer system, spokeswoman Laura Cooke said.

The virus, of the self-spreading kind known as a "worm," affected the airline's call center in Toronto and check-in systems across the country, she said.

Symantec, an Internet security company, designated the worm a "Level 4" threat -- the second-highest -- due to reports of severe disruptions on corporate networks.

Called the "Welchia" worm by antivirus companies, it targets computers infected with the "Blaster" worm, which debuted last week. Once it deletes the "Blaster" worm, the computer attempts to download a patch of the Microsoft update site, installs the patch and reboots the computer.

However, Welchia is preventing computer administrators from cleaning up Blaster, according to Vincent Weafer, senior director of Symantec Security Response. "The worm is swamping network systems with traffic and causing denial of service to critical servers with organizations."

The Blaster worm also affected some computers of Ontario's emergency response system dealing with the aftermath of last week's huge blackout across a swath of the province and eight U.S. states.

Dr. James Young, the Ontario commissioner of public safety, said the problem was "making our job more difficult."