Troj/IRCBot-P is an IRC backdoor Trojan which allows unauthorised remote access to a compromised computer via IRC channels.
The Trojan copies itself to the Windows system folder with the filename autoupdate.exe and sets the following registry entries to run this copy of the Trojan when Windows starts up:
HKLM\Software\Microsoft\Windows\CurrentVersion\Run\windowsupdate
HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices\windowsupdate