Excel® 2013 On Demand

Selecting Trusted Publishers and Locations

The Trust Center security system continually checks for external potentially unsafe content in your workbooks. Hackers can hide web beacons in external content—images, linked media, data connections and templates—to gather information about you or cause problems. When the Trust Center detects potentially harmful external content, the Message Bar appears with a security alert and options to enable or block the content. Trusted publishers are reputable developers who create application extensions, such as a macro, ActiveX control, or add-in. The Trust Center uses a set of criteria—valid and current digital signature, and reputable certificate—to make sure publishers’ code and source locations are safe ...