This domain is a subdomain that appears to be part of a content delivery network, but instead of serving files it returns a '404 Not Found' error. For anyone doing a safety check, the signals are mixed: there are no malware warnings or blacklist entries, which is good. But the total absence of contact details, company identity, or any historical record makes it hard to answer the question 'is sdn-global-prog-cache.3qsdn.com a scam?' with confidence. In practice, this is not a website meant for visitors. It's a technical endpoint that either isn't configured properly or has been taken offline. If you stumbled onto this domain, there's nothing to interact with β so there's no immediate danger, but also no reason to treat it as a legitimate service. Reviews of the domain are nonexistent, which is expected for a cache host. The safest approach is to ignore it.