Hackers in recent weeks have exploited flaws in SharePoint, a document management system developed by Microsoft Corp., to try to steal sensitive data from hundreds of victims.

A sweeping cyber espionage operation targeting Microsoft server software compromised about 100 organizations as of the weekend, two of the organizations that helped uncover the campaign said.

Microsoft recently patched two major flaws in SharePoint on-prem instances, but the effects could be long-lasting.