.dll
High riskWindows Dynamic Link Library
A shared library on Windows. Loaded by `.exe` processes to expose functions. DLLs are never run on their own — always loaded into a host.
MIME types
- application/x-msdownload
- application/vnd.microsoft.portable-executable
Category
executable
What opens this file
- Dependency Walker
- Process Explorer
- CFF Explorer
How to open by OS
Windows
- Loaded by the OS when a process needs it.
Mac
- Via Wine.
Linux
- Via Wine.
Ios
- Not applicable.
Android
- Not applicable.
Safety notes
- DLL hijacking abuses the search order to load a malicious DLL. Validate signatures and install locations.
rundll32can invoke arbitrary exports, making DLLs a common malware execution host.
Common mistakes
- Grabbing a missing DLL from a random download site is a well-known source of malware — rely on the original vendor.
- Mixing 32-bit and 64-bit DLLs in the same process fails at load time.