There is only one file type that uses the .TTARCH extension:
Telltale Games Archive
File used by games developed by Telltale Games, such as The Walking Dead, Sam & Max, and Strong Bad; used for storing game assets such as sounds and graphics; referenced by the various games to load content during gameplay.
Some TTARCH files can be viewed and extracted using Telltale Explorer.
|Quick and Easy Software Telltale Explorer||Free|
Updated: August 27, 2012