: The file inside, XXVi.aXX , is created by AxCrypt , a robust file encryption software.

: AxCrypt typically keeps the original file name and appends .axx . This suggests the original content was named "XXVi" (which could refer to a variety of things, such as the XXVI Video Player for Android). Detailed Security Review

: You cannot view the contents of this file without the AxCrypt application and the correct password or key file.

: It uses AES-256 bit encryption , which is an industry-standard for securing sensitive data.

*.axx has been classified as ransomware files | AxCrypt - Forums