Last year, the Department of Homeland Security released a scathing report detailing Microsoft’s mistakes during a 2023 hack in which China stole thousands of emails from top government officials. Two years before that, China-linked cyberattackers compromised more than 250,000 Microsoft Exchange servers.

Software giant Microsoft is at the center of cybersecurity storm after China-linked hackers exploited flaws in SharePoint servers to target hundreds of organizations.

A sweeping cyber-espionage campaign organization centered on vulnerable versions of Microsoft's server software has now claimed about 400 victims, according to researchers at Netherlands-based Eye Security.

A cyber-espionage campaign centered on vulnerable versions of Microsoft's server software now involves the deployment of ransomware, Microsoft said in a late Wednesday blog post.