Security Researchers at Trend Micro announced that AutoCAD is vulnerable to a suite of malware which sets up infected machines for a potentially devastating follow-up attack.
Once compromised, the machine with the AutoCAD installation creates an administrative account for the malware, sets up file shares, enables file-sharing protocols, and opens four ports related to file transfers. This is clearly related to the worm introduced in Peru last year that conducted billions of dollars in industrial espionage.
If you run AutoCAD, the best defense against this type of malware is to keep the host machine behind a good firewall. Not just the firewall on the device, since if compromised, the malware could bypass or turn it off, but a router or hardware firewall device. Transferring CAD files can get tricky with this new threat.
These files should no longer be assumed to be safe. Treat them as PDF's which are potentially infected. Check file sizes against expected size for similar files.