How do I execute a *.dll file

Question

I have a DLL file and want to execute it on Windows. I obtained this DLL from a Challenge site which alleges the DLL should be executed independently.

Answer 1

.DLL files are not executable in the sense that .EXE/.COM/.BAT files are executable, so I'm not sure what you mean.

You can use the Dependency Walker application that comes with the Windows SDK to interrogate a .DLL and see what functions are exported by the file.

Answer 2

You can't "execute" a DLL. You can execute functions within the DLL, as explained in the other answers. Although .EXE files and .DLL files are essentially identical in terms of format, the distinguishing feature of an .EXE is that it contains a designated "entry point" to go and do the thing the EXE was created to do. DLLs actually have something similar, but the purpose of the "dll main" is just to perform initialization and not fulfill the primary purpose of the DLL; that is for the (presumably) various other functions it contains.

You can execute any of the functions exported by a DLL, assuming you know which one you want to execute; an EXE may contain a whole lot of functions, but one and only one is specially designated to be executed simply by "running" it.

Answer 3

While many people have pointed out that you can't execute dlls directly and should use rundll32.exe to execute exported functions instead, here is a screenshot of an actual dll file running just like an executable:

While you cannot run dll files directly, I suspect it is possible to run them from another process using a WinAPI function CreateProcess:

https://msdn.microsoft.com/en-us/library/windows/desktop/ms682425(v=vs.85).aspx

Answer 4

To Run a .dll file..First find out what are functions it is exporting..Dll files will excecute the functions specified in the Export Category..To know what function it is Exporting refer "filealyzer" Application..It will show you the export function under "PE EXPORT" Category..Notedown the function name-- Then open the command prompt,Type Rundll32 dllname,functionname (dllname--name of your dll) (Functionname-- name of the function you found under the PE Export) Note:Makesure that your command prompt location is your dll file location

Answer 5

To run the functions in a DLL, first find out what those functions are using any PE (Portable Executable) analysis program (e.g. Dependency Walker). Then use RUNDLL32.EXE with this syntax:

 RUNDLL32.EXE <dllname>,<entrypoint> <optional arguments>

dllname is the path and name of your dll file, entrypoint is the function name, and optional arguments are the function arguments

Answer 6

You can execute a function defined in a DLL file by using the rundll command. You can explore the functions available by using Dependency Walker.