Run the file through an antivirus or VirusTotal before extracting.
The filename does not correspond to a widely known public guide or standard software package. Because .7z is a compressed archive format, it is likely a specific, private, or niche data dump, game mod, or technical documentation shared on a forum or specialized community (such as a wiki or discord). 525252528.7z
Since the file name is generic and numeric, before opening: Run the file through an antivirus or VirusTotal