Hello,this is lisa.
Our software Label mx barcode software is no virus and Non-plug-in, but avast says it had virus.
Please re-check and give fair to Label mx.
this software’s Download Address:Http://www.labelmx.com/zzh/lxsetup.exe
Please report the FP as explained here:
http://forum.avast.com/index.php?board=2;action=display;threadid=7779
thank you very much
Welcome to the forums, lisa. 
Hopefully, this will be fixed for you in a few days.
Sorry for the inconvenience. Hope they correct the false positive soon 