MDNSResponder.exe

Hi.
I just came across this:
C:\Program Files\Bonjour\mDNSResponder.exe

I would add that I have never installed this thing and that it has permission from my Firewall to transmit data, my antivirus does not detect it as a Trojan, and that you find everything and nothing regarding the origin and utility of this thing online...

Question: should I get rid of it, right?

Thanks to everyone who has an opinion.

Configuration: Windows XP, SP II Microsoft Firewall Avast! Home