There is a piece of malware out there written as an ObjectARX application, i.e. it will only affect AutoCAD users. It’s a China-based adware client, which Andrew Brandt at the Webroot threat blog has named Trojan-Pigrig. For full details, see here. Also, see here for AutoCAD-specific advice from the AutoCAD support team at the Without a Net blog.
Today, I tried to investigate a DWG file that one of my users couldn’t open. It wouldn’t open for me on an old 1 GB PC. Trying a PC with 4 GB didn’t help, and neither did experimenting with various releases of AutoCAD. Depending on the release, AutoCAD would either try to open the drawing and eventually die with an out of memory error, or would instantly inform me that the drawing was too big to open. I don’t have access to a 64-bit version of AutoCAD (which might possibly be able to open this monster on a PC with more than 4 GB of RAM), so the drawing is effectively useless.
The drawing is 242 MB (254,145,119 bytes), which I’m pretty sure is the largest drawing I’ve ever encountered. Based on a plot of a previous revision of the the drawing, it should be about 200 to 300 KB, i.e. one thousandth of the size it is. Looking at other oversized drawings from the same company shows that they are large because they contain lots of invisible proxy objects from a third party add-on or vertical variant of AutoCAD. Wblock will dramatically shrink such drawings, but care needs to be taken to ensure it’s not stripping out anything that might possibly be needed.
What is the biggest drawing you have ever come across? Did you discover what was making it so huge?