Stealth is a simple DLL, that will disable the default mIRC indir VERSION reply, allowing you to script your own.

Unlike most DLL’s we see that are written for mIRC, this DLL is not required to stay loaded, since it directly modifies mIRC’s memory space.
The only problem with the way this works is that there is no guarantees it will work on future versions of mIRC (designed for mIRC 6.35)
Different version changers have appeared in the past, but this should work correctly with SSL sockets, as well as IPv6 (although other DLL’s may be required for IPv6).

To add your own version reply, it’s as simple as adding something like this to the remotes section of the script editor:
ctcp *:VERSION:?:CTCPREPLY $nick VERSION mIRC $version on Windows $os

Note: Also (surprisingly?) works with mIRC running under Wine.