What happened

Eletrobras disclosed that ransomware reached part of the administrative-server network at its nuclear subsidiary Eletronuclear. The affected network was separate from the operational systems of the Angra 1 and Angra 2 nuclear plants, and the company reported no impact on plant operations. Brazilian government cyber-response and nuclear-security bodies were notified. No reliable evidence supports the supplied August 2021 date or attribution to Black Basta, a group that emerged later.

When cited sources give different casualty, damage or spill figures for this event, they’re reported side by side above rather than merged into one number. See how confidence levels work.