sun9-27.userapi.com is a subdomain of userapi.com, the content delivery and API domain used by the Russian social network VK (Vkontakte). It's not a consumer website you browse; it's a backend server that hosts images, videos, or other media for VK's platform. The 403 error you see is normal — it blocks direct access from automated tools or browsers trying to connect without the proper VK client context.
From a technical perspective, this server is well-configured. It uses a valid SSL certificate, enforces HTTPS, and loads quickly. Security checks from Google and blacklists come back clean. There's no evidence of malicious activity.
If you're wondering whether sun9-27.userapi.com is safe — the answer is yes. It's a legitimate part of a well-known service. You wouldn't buy anything here, but if you see this domain in a URL bar, it's just VK delivering content. There are no red flags that suggest a scam or fake site.