Microsoft document-sharing site

Exposed files on Microsoft's document-sharing site

The sensitive information was found via a publicly available search engine that is part of Office 365.

Security researchers said many firms mistakenly thought documents would only be shared with colleagues not globally.

Microsoft said it would "take steps" to change the service and remove the sensitive data.

Security researcher Kevin Beaumont discovered the sensitive information after using the search engine on Docs.com - a website that is part of the Office 365 online software service.