.DM File Extension

File (often audio) that has been encoded with DRM (Digital Rights Management) copy-protection; used by some cell phones for ringtones and other media clips, but can also be used for digitally signed mobile applications; can only be opened using an authorized cell phone.

Normally DM files are installed in the background using a mobile phone download and installation service such as the online Nokia Ovi Store. However, sometimes users download DM files manually and save them to the desktop. For example, a user could save a Nokia Ovi Store .SIS or .SISX application file as a .SIS.DM or .SISX.DM file.

DM files can also be created with the DRM Packager Tool for Sony Ericsson phones.