theres a thread concerning this here
https://forums.mirc.com/ubbthreads.php?ub...true#Post159504it does say what it "assumes" the trojan to be, however google doesnt seem to put up any good answers.
Either way good luck fixing it, not sure if anyone on the MIRC can help you with this, as its not really "mirc" which is causing the problem, hopefully that thread can help you somehow