Threat actors exploit SharePoint flaws to access internal systems, steal sensitive data, and carry out surveillance, impersonation, and extortion.

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.

The US agency responsible for maintaining and designing the nation’s cache of nuclear weapons was among those breached by a hack of Microsoft Corp.’s SharePoint document management software, according to a person with knowledge of the matter.