Beyond security, this version included several functional updates to improve the user experience on newer operating systems like Windows 10 and 11:
This allowed them to force the application to load a remote configuration file ( mirc.ini ) from an attacker-controlled server, potentially executing arbitrary code on the user's machine. mIRC 7.55 - SeuPirate
In versions prior to 7.55, attackers could use malicious irc:// links to pass command-line arguments to mIRC. mIRC 7.55 - SeuPirate
Updated the OpenSSL library (to v1.1.1b at the time of release) and the CA root certificates to ensure secure connections. mIRC 7.55 - SeuPirate
Added a "Follow Windows Dark Mode" option and updated Aero theme support for MDI windows.