It is still possible there is a virus in that dll, because viruses tend to try and insert themselves everywhere. It might not even be intentional. I don't really have an antivirus, just whatever came with windows 8.1, and it doesn't complain. If you want to be safe, you can still get the real dll from here: https://dl.dropboxusercontent.com/u/43784416/PowderToy/dlls.zip (may or may not work).