According to freelists.org *"It is a tool to be used by software publishers and distributors of "free" software and is intended to increase the profits of their "free" distributions"*
InstallBrain appears to be the chosen installer of a software program that you have installed. The updater service seems to be to send info back to the program makers about your use of the software (?) as far as I can make out from the features page I have linked to and info on WWWeb it tracks everything.
As far as I can work out, to stop the updater nagging to install it, you have to delete the ibu.exe (ibu = installbrain Updater) it may be in your Temp Folder or in C:/programData\IBUupdaterService\ibsu.ex\updater or in Add/Remove Programs OR all of them :(
Depending on which software program used InstallBrain as it's installer the updater may even go by a different name. First thing to try is to Clean out your temporary internet files and temp files (empty them both)