Security and Protecting Against Malicious Code

Overview

Malicious executable code, also known as malware or viruses, has become more common and can impact users of 3ds Max. If allowed to spread, malware can result in loss of intellectual property and reduced productivity.

The most common vulnerability results from allowing malicious executable code such as MAXScript, embedded in data files such as a scene file (.max) to automatically load into and execute in 3ds Max. Compiled (C++, C#) or scripted (MAXScript, Python) plugins and tools could also pose a risk. Some malicious scripts spread by editing or creating a new script in 3ds Max’s scripts\startup folder, adding code to it to load the malicious script.

Vulnerable Files

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

• 3ds Max scene files and its various flavors (.max, .maxc, .chr, .mat)
• MAXScript scripts (.ms, .mcr, .mxs, .mse)
• Python scripts (.py, .pyc)
• C++ plugins (all extensions supported by 3ds Max, .dll, .exe)
• .NET assemblies (.dll)
• JavaScript

Recommendations

The following best practices will reduce your vulnerability to malicious executable code:

• Install 3ds Max in the default program files location with User Account Control (UAC) turned on.
• Do not run 3ds Max with Administrator privileges.
• Keep your virus definitions current.
• When installing 3rd party plugins, make sure that the installed files are digitally signed with a certificate issued by a reputable source, such as VeriSign.
• To verify the digital signature of a binary file, open its File Properties dialog, and navigate to the Digital Signatures tab. If this tab is missing, the file does not have a digital signature. For more information see the Digital Signatures for executable files topic.
• To verify the digital signature of MAXScript files, see the Digital Signatures for script files topic.
• Never run an unknown MAXScript or Python file without first inspecting it for signs of malicious or suspicious code.

Digital Signatures for Executable Files

A digital signature is a block of encrypted information added to certain files to identify the originator (author) and indicate whether a file has been altered since the digital signature was applied.

Executable binary or text (script) files with digital signatures provide the following benefits:

• Users of executable files are provided with reliable information about who created the files, and that they haven't been modified to contain malicious code.
• Authors of executable files are provided with reliable verification that they have not been modified since they were digitally signed.
• You can examine a file's digital signature through a chain of trust back to the root certificate issued by a trusted Certificate Authority (CA)

Digital Signatures and Binary Files Associated With 3ds Max

The following file types in the 3ds Max product distribution are executable, and have been digitally signed to better protect you: EXE, DLL, DLZ, DLU, DLO, DLM, DLC, DLI, DLT, DLE, DLV, DLK, DLB, DLF, DLR, BMF, BMI, BMS, FLT, GUP, DLH, DLN, DLA, DLS, DLY, DLX.

The digital signature for executable files can be accessed by right-clicking the file, clicking Properties, the Digital Signatures tab, the name of the signer and the Details button, and then View Certificate. Note that the file extension must be .DLL for this to work, so the recommended approach is to make a copy of the file and change its extension to .DLL, then check the File Properties.

For example, this is what this File Properties dialog looks like for 3dsmax.exe: