vkvd341.okcdn.ru is a subdomain that doesn't load a normal webpage right now, which raises immediate questions. If you came across this address while browsing or in an email, there's very little information to verify who runs it. The domain ownership is hidden, the site blocks all search engines, and there's no public record of it in the Wayback Machine — meaning it's either brand new or deliberately kept off the radar.
For a technical asset like a CDN endpoint, some of these things can be normal, but the fact that it returns a 400 error and hides its owner makes it hard to recommend for any personal use. If you're asked to visit this site or enter any information on it, stop and double-check the source. There's not enough evidence to call it a scam, but there's also not enough to call it safe. Treat it as a placeholder that doesn't inspire trust until proven otherwise.