Files downloaded from unofficial sources frequently contain malware or trojans embedded within the executable.
Autodesk software is typically licensed via subscription or seat-based models. "Portable" versions found on third-party sites are often unauthorized distributions that violate EULAs. Portable.Autodesk.AutoCAD.2010
The Legacy of Autodesk AutoCAD 2010: Why Professionals Still Look for Portability Portable.Autodesk.AutoCAD.2010