Microsoft announced last year that it was retiring all SHA-1 signed content from Microsoft Downloads in this blog post since the SHA-1 algorithm is no longer considered secure. The original timeline was stretched out a bit due to COVID-19, but as of January 2021 this content is no longer hosted by Microsoft servers.
This impacted the legacy DirectX SDK, the DirectX End-User Runtime, and the DirectX End-User Runtime Web Installer. In January 2021 they were removed from the Microsoft Download Center. As of February 20, 2021, these three downloads have been republished using SHA-256 signing for the ‘outer’ containers–there’s been no change to the contents or binaries. The payload DLLs are still using SHA-1, and there are known security issues, so it is highly recommended you move to the replacements mentioned in this post.