If you can provide the where you saw this or more context about what you were looking for (e.g., software, music, library tools), I can help narrow it down further. Blog - ABCD Global

: Compressed .rar files from unknown sources can contain malware. If you intend to open it, ensure you use an updated antivirus and consider opening it in a "sandbox" environment. AB_A-B-C-D-11.December.2022.rar

However, based on the naming convention, here are the most likely possibilities: If you can provide the where you saw

: The "ABCD" prefix is often associated with the ABCD Update System used for managing integrated library systems or similar database frameworks. A file with this specific date (December 11, 2022) might be a manual backup or a localized patch for such a system. based on the naming convention