Apple Archive
From Just Solve the File Format Problem
An Apple Archive is a proprietary compressed archive format, based on LZFSE, available on recent MacOS systems.[1][2] Archived files can be made via command line[3] or included "Archive Utility".[4]
File Information
AAR archive files by default using LZFSE begin with the hex values "70627A65", but also can use the algorithm's: lzma "70627A78", lz4 "70627A34", zlib "70627A7A", and raw "41413031".