7-Zip supports strong AES-256 encryption, so if 74sardine.7z is encrypted, you will need a password to access its contents.
Opening the archive within 7-Zip File Manager to see the contents without extracting. If you can tell me: What is inside the file?
Right-clicking the file and selecting "Extract Here" or "Extract to 74sardine/" using 7-Zip.
You can extract this file using the 7-Zip software on Windows or similar archive utilities on other systems.
with it (e.g., extract it, open it, check for security issues)?