JANESVILLE -- City employees are spending the weekend flushing a computer virus that knocked Janesville's website offline and affected millions of files.
The virus was let into the city computer network Thursday when city employees opened a contaminated email attachment, The Janesville Gazette reported.
The virus took down the city's website and its servers, a financial transaction program and other systems, including a program that digitally connects everything in the city and is the "backbone of the city's network infrastructure, City Manager Mark Freitag said.
Freitag said the city website was down Thursday afternoon and evening, but the public wasn't otherwise affected by the virus attack.
"We were able to ensure that, minus the website being down yesterday (Thursday) afternoon and last evening, for the public there was no evidence of degradation in service capabilities," Freitag said.
Gordy LaChance, information technology manager for the city, said it's unlikely any data or information will be stolen or left unsecured.
This one really did a number on us," LaChance said.
Employees will work in 12-hour shifts over the weekend to flush the virus and restore the network. It could take dozens of staff hours through Tuesday or beyond to have everything back to normal, city officials said.
Officials said the attack was random, and the source is unknown.
Freitag said the city can redouble its network security training efforts, but "there's always a way in."
"Even as much training as we go through, sometimes that attachment looks pretty normal, and you click on it, and next thing you know, you got a problem," he said.
