Autodesk has released Service Pack 1 for AutoCAD 2013 and AutoCAD LT 2013. 32-bit and 64-bit versions of this update can be found at the following links:
This update is only for AutoCAD and AutoCAD LT and cannot be applied to vertical products that are based on AutoCAD 2013.
Before installing Service Pack 1, I strongly recommend you review the associated readme file for installation instructions and details about the primary issues that are resolved by the service pack.
This service pack introduces new system variables for managing malware issues in AutoCAD. Details can be found in the readme file and in the technical solution, AutoLISP and VBA Security Controls in AutoCAD 2013 SP1.