file is a "Visual LISP Executable." It acts as a container for multiple AutoLISP routines and resource files (like dialogue boxes) compiled into a single file.

**.vlx files are compiled AutoCAD LISP applications. Downloading them from untrusted sources can be risky because:

Most CAD-specific malware goes undetected by standard antivirus software because it doesn’t look like traditional executable code. A file may pass a virus scan today but contain a time-delayed trigger.