Perflib_Perfdata_5e0.dat
Perflib_Perfdata_5ec.dat
Perflib_Perfdata_630.dat
Perflib_Perfdata_648.dat
They are not infections.
Any app or program that installs a performance monitoring function can create those, and they ar safe to delete. You can stop them being created by doing this:
To stop your Performance Logs and Alert service, click Start>Run.
Type “services.msc” (no quotes) in the run dialog box and hit your enter key.
Select it from the list and double click it. Click the “Stop” button.
Reboot.