It is definitely not an IRC client, it's a script that works WITH mIRC, it is not an IRC client itself. If it's distributing mIRC.exe as part of the script package then it shouldn't be.

Do be aware, mIRC isn't a file trading program it is meant for chatting and the occasional file-swap between friends. Downloading warez is also illegal in 99.9% of cases and a good way to catch a virus - not to mention very poor quality.