Autodesk has released the first Service Pack for the AutoCAD 2013 family. SP1 for AutoCAD 2013 (plain AutoCAD plus the Design Suites versions) and AutoCAD LT 2013 fixes a series of problems reported using the CER (Customer Error Reporting Utility).
Besides that, SP1 introduces new protection mechanism against viruses and malware attacking AutoCAD users through the autoloading of AutoLISP and VBA code (typically acad.lsp). This mechanism includes several settings which allow to disable or specify autoloading.
The new "/nolisp" runstring parameter for acad.exe can completely disable any execution of AutoLISP code. The LISPENABLED system variable then reflects the "nolisp" status.
The AUTOLOADPATH variable specifies paths used to load the default customization files (acad.lsp, acad.fas, acad.vlx, acaddoc.lsp, acaddoc.fas, acaddoc.vlx, acad.dvb); its default value "" means loading similar to the older versions.
The AUTOLOAD variable can disable automatic loading of the above mentioned files on AutoCAD start (use the latest version of the VBA Enabler)
You can download the SP1 (the re-released SP1.1) from Download or directly from Autodesk support