Nortons did not find anything either but it is only as good as the definition and if this file has never been submitted then they will have no way to identify it as a virus. Search and Destroy Spybot listed that dll file as a keylogger. The dll file is placed by the DARKNeZZ.exe...so that is why I am wondering. The search and destroy program is good at finding spy related software. I am not saying 100% that this is a key logger but it looks like it from what I have been reading. I am not using it....anyone that does that is up to them.
Here is a link to S&D spybot remover..it too has definitions that you update just like anti-virus software. Make sure you keep it up to date.
http://security.kolla.de