The page will serve to provide general rules to follow for anonymity while connecting to IRC servers hosted on clearnet, Tor or I2P.
Copied from: http/ugha.i2p/HowTo/IrcAnonymityGuide and http://3suaolltfj2xjksb.onion/hiddenwiki/index.php/IRC_Anonymity_Guide
The obvious "don't"s
- Don't enter/use information that can be associated with your real identity. This includes passwords, nicknames, full names, idents, etc. Also, if you have an email i.e. `email@example.com` linked to your facebook account, don't use this email for IRC registration.
- Never share your social profiles, phone numbers (incl. WhatsApp), telegram nicks, etc. Sharing this information may result into charging a criminal case against you if you do illegal things such as carding or just visit relevant resources.
- Don't follow unknown/suspicious links. Always use Tor when following links.
- Do not connect to unknown IRC servers. The majority of IRC clients' security holes can be exploited only by the server administrators.
- Never accept a DCC request unless you know what you are doing.
- You shouldn't act suspicious or nosy, as this will decrease the level of trust people have in you. For example, don't ask `hey bro, where are you from?` or for a facebook profile, as this may result into thinking you are an undercover police agent. Don't try to send CTCP/DCC requests.
About XChat / HexChat
XChat before version 2.6.x sends your hostname every time it connects to an IRC server, on UNIX-like OSs it is your username and on Windows machines it is your machine name (See uname -n for the value sent). This behavior cannot be overridden, and requires an IRC bouncer (like BNC) in order to change/hide the hostname.
Pidgin is an excellent open source IRC client with plugins for OTR. However one thing that users should be careful of is that if you don't put a fake name in the IRC real name field,Pidgin will by default fill it in with your machine's hostname. The obvious solutions here are to give it a fake "real" name or to use a nondescript hostname (e.g. "anonymous").
It is not possible to disable CTCP or DCC in Pidgin. If you are connecting to a Tor or I2P IRC it is advisable to use Xchat or IRSSI instead.
The use of mIRC is discouraged and highly not recommended! mIRC is a closed source client, which means you can't know whether there is hidden functionality compiled within the program.
However, in case you absolutely want to use mIRC, you should always keep the version up to date. This is because of the fact that mIRC has had a history of critical remote exploits. Also, as it's the most popular IRC client for Windows, it probably gets the most attention from hackers/crackers.
Avoid using suspicious mIRC scripts, as many of them include backdoors.
CTCP stands for Client To Client Protocol, it's a method for exchanging information between two IRC clients. The most common CTCP commands (requests) include ACTION, VERSION, PING, CLIENTINFO, USERINFO, etc.
CTCPs are bad, because they they can potentially reveal information about you, your IRC client, the OS you are using, etc.
Even though the most popular CTCP command, ACTION, is not harmful, it's probably the only one. CTCP ACTION will be issued with the /me command in most IRC clients. Also, the majority of IRC clients will not block CTCP ACTION when you ignore all CTCPs. (Which is good)
Most notably, CTCP VERSION can be used to get the name and version number of the IRC client you're using. For example, mIRC might reply with "mIRC v6.16 Khaled Mardam-Bey", and some IRC clients even go as far as revealing the kernel version, CPU and more ("xchat 2.0.10 Linux 2.6.8-1-686-smp [i686/2.79GHz/SMP]"). Fortunately, many IRC clients provide a way to fake the VERSION reply. However this is out of the scope of this guide. On the contrary, mIRC even includes protections that keep you from hex editing the VERSION reply.
CTCP TIME can be used to find out the timezone you live in, CLIENTINFO can be used to find out about the commands your IRC client supports, etc.
CTCP PING can be used to determine the round-trip time between two cliens, through the IRC server. This can potentially be used to find out the tunnel length of other users, but ping times through I2P are generally random enough. On the contrary, most clients send a timestamp when requesting CTCP PING, so if you ping anybody they'll probably be able to determine the timezone you're in.
DCC stands for Direct Client-to-Client, it is a protocol for establishing direct connections between two users, either for private chats or file transfers. Since these connections are direct (they don't go through the IRC server), the participants would need to know each other's IPs, which is obviously bad. (See also: HowTo/DccOverI2p)
Technically, DCC uses CTCP for the handshake, but most IRC clients won't block DCC when you tell them to ignore CTCPs.
XChat / HexChat
To disable CTCP in XChat to go settings, Advanced, and then click on CTCP Replies. This will bring up a window with a list. Delete everything from this list.
Yuo may also type:
/ignore * CTCP DCC (Note: This also ignores CTCP ACTION from all users.)
/ignore * CTCPS (Ignores everything but ACTION and DCC)
/ignore * DCC (Ignores all DCC commands)
/ignore -wt *
/ignore -wd *
Disabling mIRC CTCP Client Information Queries
Responses to CTCP FINGER, CTCP TIME, and CTCP PING requests made against your mIRC client can be disabled by adding the following lines to your Remote script (press ALT-R and select the [Remote] tab):
ctcp 1:FINGER:*:echo 4 -se [ $+ $nick FINGER] denied | halt ctcp 1:TIME:*:echo 4 -se [ $+ $nick TIME] denied | halt ctcp 1:PING:*:echo 4 -se [ $+ $nick PING] denied | halt
With these scripting commands added to your Remote script, other IRC users will simply receive no response whatsoever from your mIRC client upon attempting to gather information about you from it using any of these commands. You will additionally be alerted to all such failed attempts in your status window (the "denied" messages).
To additionally prevent mIRC from sending CTCP VERSION responses, the mirc.exe executable must be hex edited. For version 6.35 of mIRC (the latest as of this writing), make the following changes with a hex editor:
Offset Old New 0006354C 85h -> B0h 0006354D C0h -> 00h - Offset Old New 000E6BEF 74h -> 90h 000E6BF0 27h -> 90h - Offset Old New 000E74FA 74h -> 90h 000E74FB 36h -> 90h - Offset Old New 001F6FA4 56h -> 00h 001F6FA5 45h -> 00h 001F6FA6 52h -> 00h 001F6FA7 53h -> 00h 001F6FA8 49h -> 00h 001F6FA9 4Fh -> 00h 001F6FAA 4Eh -> 00h
Again, these patches apply only to mIRC 6.35. Once these binary patches are made, you may then add the following line to your Remote script so that, as with the other CTCP commands above, you will receive alerts when others have attempted (and failed) to retrieve your client version information:
ctcp 1:VERSION:*:echo 4 -se [ $+ $nick VERSION] denied | halt
Note: Adding the above line to your Remote script without also applying the binary patches will not prevent mIRC from sending your VERSION information. Specifically, mIRC is internally boobytrapped to ignore "halt" commands issued by Remote scripts during CTCP VERSION scripting events, and that is why the additional binary patching is necessary to "re-enable" sensitivity to "halt" during CTCP VERSION scripting events. No such internal boobytrapping exists for CTCP FINGER, CTCP TIME, and CTCP PING events in remote scripting, and thus issuing "halt" upon them in Remote scripting is all that's necessary to completely disable them.)
ViRC (and ViRC 2.00)
Choose File -> 'Script editor...' from the menu. Choose 'local.lib' from the drop-down box. Copy-paste following lines to the header section, below the comments:
//Halts all CTCP requests from being processed, except ACTIONs if [$strtrim($3)]!= [ACTION] AbortEvents endif
Click on the 'Save & Rehash' button. That should do it.
(Thanks to DrWoo for the information about ViRC)
Many UNIX IRC clients (including irssi) send the computer's hostname to the IRC server while connecting.
Supplying a bogus hostname:
/set hostname hidden.i2p (Sets your hostname to hidden.i2p)
XChat >= 2.6.x
The hostname is not sent
XChat < 2.6.x
The value can only be changed by hacking the source and changing the USER command sent to the server in src/common/proto-irc.c and recompiling. Example:
--- proto-irc.c 2004-10-26 04:17:09.000000000 +0000 +++ proto-irc_hacked.c 2005-03-05 17:11:37.140000000 +0000 @@ -61,7 +61,7 @@ tcp_sendf (serv, "NICK%s\r\n" "USER%s%s%s:%s\r\n", - serv->nick, user, hostname, serv->servername, realname); + serv->nick, user, "myhost", serv->servername, realname); }