Dll Injection - What is possible with it?

Question

I was browsing the internet lately, when I stumbled upon Dll Injection.

I think its an interesting subject but, I have no clue what the purpose of it is?

I have

Answer 1

In computer programming, DLL injection is a technique used to run code within the address space of another process by forcing it to load a dynamic-link library.[1] DLL injection is often used by third-party developers to influence the behavior of a program in a way its authors did not anticipate or intend. For example, the injected code could trap system function calls, or read the contents of password textboxes, which cannot be done the usual way.

Source and more info here: http://en.wikipedia.org/wiki/DLL_injection You can find also some good references to external sources.

Dll Injection can be used for a good reason when you have a legacy system with no source code for it and you need to change its behaviour. It is a dirty hack though and should be used as a last resort, IMO.