While the exact contents depend on where you got the file, "MM_19" is a common shorthand in specific technical fields:
Strings like "MM_19" frequently appear in encoded data within SEC EDGAR filings , though these are typically parts of larger text documents rather than standalone downloadable archives. MM_19.7z
The Official 7-Zip Download is the standard and most reliable tool. For macOS: You can use The Unarchiver or Keka . While the exact contents depend on where you