The CTX file extension is associated with the Visual Basic an integrated development environment that allows users to create programs and scripts for Microsoft Windows operating system. The *.ctx file stores user control binary data. Saved along with the .CTL file that defines the ActiveX control.
Game script encoded by the Information Concealment Engine (ICE) cipher; used by Valve games such as Team Fortress 2 (TF2) and Counter Strike; used for obfuscating game scripts so that users can't tamper with them easily. CTX files can be converted to .TXT files using Ctx Converter.