It primarily uses the LZMA and LZMA2 algorithms, which provide superior space savings for text and source code compared to the standard ZIP format.
Be cautious of where the file originated. Malicious versions of the 7-Zip installer itself have been found on unofficial sites like 7zip.com (the official site is 7-zip.org ). TreeHertz.7z
If you must extract the files, do so within a Virtual Machine or a "harsh environment" to prevent any potential malware from accessing your primary system. It primarily uses the LZMA and LZMA2 algorithms,