Identifying DLL Dependencies

Dynamic-Link Libraries (DLLs) are executable software applications that cannot run independently. These libraries usually have the file extension .dll, .ocx (for libraries containing ActiveX controls), or .drv (for legacy system drivers). A dependency is the degree to which a program module depends on another to run. When one program depends on another, both of them must be installed and authorized to work together.

You must independently identify all DLL dependencies to authorize the DLLs required for your software applications to work. The Authorization Wizard does not identify software DLL dependencies for authorization. After you identify DLL dependencies, you can identify and assign all required files to the corresponding application file group.

Danger: You must identify and authorize DLLs separately for Application Control, rather than scanning for these files with Scan Explorer templates or using the Authorization Wizard, because malicious software applications can be hidden in DLLs.

DLLs require independent identification because applications automatically load DLL files:

• Listed in an application DLL/EXE import table before loading a software application, to resolve DLL references.
• Explicitly by the application at run time.
• As dependencies of DLLs that use other DLLs.