The attack was confirmed on Sunday and the group claiming to be behind it says they have obtained 280 gigabytes of data. In terms of size, it is significantly more than the attacks that were carried out, for example, on the system supplier Miljödata in September and Sportadmin in January this year.
But the extent depends on what was in the data, according to IT security expert Karl Emil Nikka from Stöldskyddsföreningen.
If it's text files, it's enormous amounts of data that they have obtained. But if it's an image bank or video, it's not the same amount, he says.
Svenska kraftnät has not released detailed information about what it is. But they have said it's about "a limited external file transfer solution".
It could be a service used to transfer files that are too large to email, then it's probably less danger. It can also be a solution used to communicate securely with external parties, then it's worse, says Karl-Emil Nikka.
