About Protecting Against Malicious Code

Several security measures and practices can protect you against malicious executable files.


Malicious executable code, also known as malware or viruses, has become more common and can impact users of AutoCAD. If allowed to spread, malware can result in loss of intellectual property and reduced productivity. Two common categories include automatically loaded AutoLISP files and VBA (Microsoft® Visual Basic® for Applications) macros. More sophisticated attacks that compromise or steal intellectual property include malicious ARX applications, object enablers, and DLLs (dynamic link libraries).

The most common vulnerability results from allowing executable code to co-exist with data, such as

For example, project-based executable files bundled together with drawings in a ZIP file might include edited versions of acad.lsp, acaddoc.lsp, and FAS and VLX files that contain malicious code. When the contents of the ZIP file are extracted into a folder and AutoCAD is launched by double-clicking a DWG file, the LSP files are automatically launched as well.

Also, many viruses try to propagate themselves by editing acad.mnl, adding a line in it to load itself.

Security Countermeasures

AutoCAD security countermeasures minimize the possibility of executing malicious code by providing controls that

Malicious code can be included in the following types of files:

Important: Using the /safemode switch also prevents the AutoCAD Express Tools and most AutoCAD command tools from functioning, and should only be used temporarily in situations where you suspect that malware has been installed on your system.


The following best practices can minimize your vulnerability to malicious executable code:

Note: AutoCAD LT® does not run AutoLISP, VBA, or other applications, and does not require these security measures.