At the heart of FileMagic lies our patented binary-analysis engine. Rather than relying on file extensions alone, FileMagic inspects each file’s signature at the lowest level, automatically identifying its format and selecting the optimal internal routine to open it. https://www.filemagic.com/en/uncommon-files/c3m-file-extension/c3m-files-what-it-is-and-how-to-open-it/