Yep, spyware and viruses can manifest themselves in .DLL files. Basically, it enables them to "infect" an applicaton by simply telling the application to reference the DLL's code.

You might want to read some of the sticky threads in our Security forum on what to do with those files, as the "Helping Yourself" thread may have some good tips.

Do a little Google research on the dll files...if you can find out what program they were installed with or a virus that uses them maybe you can find out how to remove it.