A hacker or hacker group might have stolen healthcare data for more than half of Norway’s population, according to reports in local press.

The attack took place on January 8 and came to light this week when Health South-East RHF, a healthcare organization that manages hospitals in Norway’s southeast region, announced a security breach on its website.

The organization said HelseCERT, the country’s CERT division for the healthcare sector, had identified suspicious traffic coming from Health South-East’s computer network.

An investigation by the IT staff at Sykehuspartner HF —Health South East RHF parent company— revealed evidence of a severe data breach.