There is only one file type that uses the .SC2MA extension:
StarCraft 2 Map Data File
Map information file used by StarCraft II: Wings of Liberty, a real-time strategy game; contains data for a map being played online; used for downloading and storing map data for Blizzard's Battle.net online gameplay.
S2MA files are stored in Blizzard's .MPQ file format. Therefore, you can rename their extension to .mpq and open them with any MPQ extractor or editor. S2MA files can contain various map data, such as settings, triggers, version information, localization text, graphics, and other information.
In Windows Vista and Windows 7, S2MA files are located within subdirectories of this directory:
In Mac OS X, they can be found in the subdirectories of the following directory:
Updated: August 29, 2010