Trojan:Win32/Ircbrute is a generic detection for multiple families of malware. Many of these are backdoor Trojans that use Internet Relay Chat (IRC) for remote command and control of the affected machine.
Trojan:Win32/Ircbrute detections may also be used for components of malware. Such components may modify system settings by performing such actions as disabling Windows firewall, Windows updates, network shares and anonymous network share access.
Upon execution, Trojan:Win32/Ircbrute usually writes a copy of itself to the Windows system folder, and modifies the registry to ensure that this copy is executed at each Windows start. Trojan:Win32/Ircbrute may then try to connect to an IRC server and wait for commands from a remote attacker.
Alert notifications or detections of this malware from installed antivirus or security software may be the only other symptom(s).