If you're having problems deleting the mIRC because its already running you will have to manually kill the program. This is a bother because the virus uses the "HideApp" executable to remove its system tray icon and make itself a windows service (which won't show in your ctrl+alt+delete task list and will survive logout - although I'm not certain if this behaviour also happens in XP).
You should be able to find and kill the process with a 3rd party process manager like
PrcView (your virus scanner itself might have to ability to forcefully kill - so give that a try too), the hostile .exe's probably won't call themselves 'mirc.exe' so you'll have to verify with your virus scanner which programs need to be zapped. Once they're no longer running you should be able to delete them.
