Yes. While Autodesk has released 2023, 2024, and 2025 versions, the 2021 release remains highly sought after for three reasons:
Autodesk does not offer legacy versions like 2021 for free after newer releases (2023, 2024, 2025 are now current). You cannot legally download Civil 3D 2021 without a valid subscription or trial. Avoid third-party websites offering “cracked” or “pre-activated” versions—they often contain ransomware, spyware, or keyloggers.
A: Yes, if the file name comes from akn (Autodesk Knowledge Network) or autodesk.com. The "sfx" stands for Self-Extracting. No if it comes from a torrent site named "CrackzTeam.rar."