The Lovsan computer worm has so far failed to cause any significant damage in Finland. Estimates put the number of computers affected at less than 10,000.
It was set to target the Microsoft update site at midnight Friday but the company took the targeted web page offline. The company claims it has neutralised the virus.
Finland's Communications Regulatory Authority says the country's tele service providers took preventive action in good time.
On Thursday, the Nordea Bank was forced to close many branches after the Lovsan virus affected its computer system.
YLE24