IRC was originally a plain text protocol (although later extended), which on request was assigned port 194/TCP by IANA. However, the de facto standard has always been to run IRC on 6667/TCP and nearby port numbers (for example TCP ports 6660–6669, 7000) to avoid having to run the IRCd software with root privileges.
For connecting to a server it is required merely a nickname. Once connection is established, the first thing the server does is a reverse-dns to your ip:
It seems that overall there are two kinds of users: operators and ordinary users. For logging in as an operator it is required a username and a password (and in many occasions a particular hostname, ip and even a particular hostmask). Within operators there are different privilege levels wherein the administrator has the highest privilege.
Default ports: 194, 6667, 6660-7000
PORT STATE SERVICE
6667/tcp open irc
IRC can support TLS.
nc -vn <IP> <PORT>
openssl s_client -connect <IP>:<PORT> -quietHere you can see how to connect and access the IRC using some random nickname and then enumerate some interesting info. You can learn more commands of IRC here.
#Connection with random nickname
USER ran213eqdw123 0 * ran213eqdw123
NICK ran213eqdw123
#If a PING :<random> is responded you need to send
#PONG :<received random>
VERSION
HELP
INFO
LINKS
HELPOP USERCMDS
HELPOP OPERCMDS
OPERATOR CAPA
ADMIN #Admin info
USERS #Current number of users
TIME #Server's time
STATS a #Only operators should be able to run this
NAMES #List channel names and usernames inside of each channel -> Nombre del canal y nombre de las personas que estan dentro
LIST #List channel names along with channel banner
WHOIS <USERNAME> #WHOIS a username
USERHOST <USERNAME> #If available, get hostname of a user
USERIP <USERNAME> #If available, get ip of a user
JOIN <CHANNEL_NAME> #Connect to a channel
#Operator creds Brute-Force
OPER <USERNAME> <PASSWORD>nmap -sV --script irc-botnet-channels,irc-info,irc-unrealircd-backdoor -p 194,6660-7000 irked.htblooking up your hostname