If the source is unknown, do not extract it on your primary machine. Use a Sandbox or a Virtual Machine.
Musicians like TheFatRat often share open-source stems for remixes via 7z archives. Noah.7z
Use a tool like 7-Zip to "Test" the archive. This will list filenames without extracting them. If the source is unknown, do not extract
It could be a digitized collection of works by Mordecai M. Noah , a prominent 19th-century American journalist and playwright. If the source is unknown