Funnily enough, a friend of mine on Saturday said that mIRC was being detected as spyware on their computer, and it was the one that they downloaded from mirc.com - if you are downloading it from mirc.com, try uninstalling the one you got and download from a different location.
If it STILL detects it as spyware (or whatever riskware is), then I should imagine it's a false positive. If not, then for some reason Kerspersky doesn't like mIRC, but mIRC is still perfectly safe to run.
Regards,