The location AppData\Local\Temp\_avast_\ is where avast unpacks or sends files to be scanned. It is highly unlikely that you would find any information on the unp200541910.tmp file as it is a uniquely named temporary file (7.dll is also somewhat strange). Files in the _avast_ temp folder should be cleared after a successful scan.
The VT results are two weeks old, if it isn't very current then it is best to have VT rerun the scan. Also the file name is different to what you mentioned 7.dll in the topic subject.