Microsoft has warned of active cyberattacks exploiting a previously unknown vulnerability in its SharePoint server software, widely used by government agencies, businesses, schools, and healthcare systems for document sharing and collaboration. The company is urging organizations to apply security updates immediately to protect on-premises SharePoint servers, noting that cloud-based SharePoint Online in Microsoft 365 is unaffected. Details of the Attack The attacks, identified as a “zero-day” exploit targeting an undiscovered flaw, have compromised tens of thousands of servers globally. Attackers are bypassing multi-factor authentication (MFA) and single sign-on (SSO) protections to gain privileged access, exfiltrating sensitive data, deploying persistent backdoors, and stealing cryptographic keys. Experts warn that patching alone may not fully eliminate the threat, as attackers can manipulate systems...