How to Identify What an Unknown DLL Does

Static identification

1. Preserve the file and record hash, path and timestamps.
2. Inspect version resources and digital signature where present.
3. Determine PE architecture and managed/native type.
4. Review imports, exports, strings and COM registration clues.
5. Search installers, configuration, source and dependent executables.

Confirm use safely

Observe loading and calls during a controlled workflow on an isolated system. Location and filename are clues, not proof. Do not register or execute an unknown library merely to identify it.

Use DLL troubleshooting when loading fails, dependency analysis, COM analysis and the pillar.