No it isn't a virus.. it is what is known as riskware, click here if you click on the not a virus link and scroll down to IRC clients you will get the following description.
These utilities provide access to IRC channels. Many IRC clients, especially mIRC, incorporate powerful script languages which automate the IRC client. This functionality can be exploited to write Trojans and IRC worms. When installing a Trojan IRC program on a victim machine, hackers will often also surreptitiously install an IRC client as well.