STOCKHOLM, May 12 (Xinhua) -- Sweden's Timra municipality was struck by a massive cyber attack Friday afternoon, Swedish public broadcaster SVT reported.
A variation of the WannaCry virus has infected Windows system and encrypts files locally and on shared services, and at least 70 computers were affected, the report said.
Shortly before 3 p.m., screens turned blue and then black on several of the municipalities' computers. After the computers were rebooted, users got a message saying that the computers were encrypted and they had to pay to regain access to the content.
Right now it appeared that there was no risk to life or health, according to Sweden's national Computer Emergency Response Team.
So far it unclear who is behind the attack.
When Andreaz Stromgren, head of the municipality's administrative offices, went home for the day, about 70 computers were affected. He estimated that as many as 100 could have been infected before they stopped it from spreading.
Some of the administrative personnel in the municipality were not able to do their work. But no one's life or health appear to be at risk, he said.
"We followed up our most vulnerable activities affecting life and health immediately. Our nurses who work with health care are not affected. Home health care and senior housing are not affected at all," Stromgren was quoted by SVT as saying.
The virus spreads through computers that are turned on in a network.
At least 74 countries were struck by the so-called ransomware campaign, SVT reported.
