One of the hacked organizations reportedly includes the U.S. agency responsible for maintaining the country's stockpile of nuclear weapons. China-backed hackers have been observed carrying out the hacks targeting SharePoint servers.

The Department of Energy, which oversees the agency that manages the US nuclear weapons stockpile, confirms it was affected by the SharePoint bug, but says it was 'minimally impacted.'

A critical vulnerability in on-premise SharePoint servers allowed state-backed hackers to breach governments and institutions worldwide. Experts are questioning why more hasn't been done or said.