I trashed the "open any files" and the pop-up has gone.
'Trend Micro' was worded at the base of the pop-up window.
Good news, happy to have helped, but I hope you no longer actually need that app (as was suggested by your having had it in the first place).
I guess I'm still curious about the "Trend Micro" connection, but since it's no longer of any consequence, I'm sure it won't make me crazy.
