usually there are some info here

sigcheck:
publisher…:
copyright…:
product…: n/a
description…:
original name: n/a
internal name: n/a
file version.:
comments…: n/a
signers…: -
signing date.: -
verified…: Unsigned

anyway as he say it can be Brothersoft Toolbar…
you may check ad/remove programs to see if you have it installed ?