Only download archives if you know exactly who uploaded them. If the link came from an unknown sender, it is likely a security threat.
The phrase typically refers to a specific file or folder structure often associated with distributed digital asset packs, software collections, or, in some cases, suspicious download links found in forums and spam emails. What is "pack 1522.7z"? Dropbox - pack 1522.7z - Simplify your life
If you do download it, use a service like VirusTotal to scan the .7z file before extracting its contents. Only download archives if you know exactly who uploaded them