Malware

Hi, can anyone help with this message I'm getting in a constant little window?

It says..... "MainPanelSearchDaemon" will damage your computer.

This file was downloaded on an unknown date.

It has the typical "Report to Apple" Tick box and below this are two buttons, 1 - Show in Finder and 2 - OK

Neither of these buttons actually do much. Click either and the window just closes then reopens.

As far as I know I haven't downloaded anything apart from Apple stuff and this box just appeared after it being left on Sleep for about a week.

Any help would be much appreciated thank you.