U.S. nuclear weapons agency was among those breached in a Microsoft SharePoint hack

The National Nuclear Security Administration was among organizations breached in a recent Microsoft SharePoint cyberattack attributed to Chinese state-sponsored hackers.

The zero-day vulnerability attack targeted governments and businesses worldwide, affecting the NNSA (which manages America's nuclear weapons arsenal), the Department of Energy, and various U.S. agencies. While no classified data was reportedly stolen from NNSA systems, the breach highlights ongoing cybersecurity challenges. Microsoft identified Chinese hacking groups including Violet Typhoon and Linen Typhoon as responsible parties, with the vulnerability first discovered at a Berlin hacking contest offering $100,000 prizes for SharePoint exploits.

• Chinese state-sponsored hackers exploited SharePoint zero-day vulnerabilities to breach government and business systems globally
• The NNSA breach marks the second major attack on the agency through third-party software, following the 2020 SolarWinds incident
• Microsoft has issued multiple patches while facing increased scrutiny over its cybersecurity practices and Chinese engineering partnerships
• The vulnerability particularly affects organizations running SharePoint locally rather than through Microsoft's cloud services