NoCheatPlus
Detect and fight the exploitation of various flaws/bugs in Minecraft!
Introduction
NoCheatPlus attempts to prevent cheat clients from exploiting weaknesses of Minecraft or its protocol, making your server more safe. Checks cover a wide range of issues including flying and speeding, fighting hacks, fast block breaking and nukers, inventory hacks, chat spam and other types of malicious behaviour. For a more complete list have a look at the Features Page.
NoCheatPlus puts emphasis on configurability and allows you to customize actions that are carried out when a player fails a check (e.g. silent cancelling, executing commands, just logging). Bypass permissions allow to control what check to apply for which players, all checks can be deactivated in the configuration, also having the option for world-specific configuration files. Many checks allow more detailed configuration to adjust sensitivity.
Certainly NoCheatPlus is not a magical bullet, it uses a lot of heuristics and even guessing, so you will encounter false positives here and there and also not catch every single violation. Example video of how NoCheatPlus blocks cheats (outdated plugin version).
NoCheatPlus was introduced by NeatMonster, building on the code base of NoCheat by Evenprime.
Recommended
The following plugins might be useful to have a look at.
ProtocolLib
Allows NoCheatPlus to activate packet-level checks, covering a range of exploits that can't be monitored using ordinary means. Since roughly Minecraft 1.7.10, the fight.speed check can't work as expected anymore, due to changes in CraftBukkit. With ProtocolLib this can be repaired.
CompatNoCheatPlus (cncp)
Make plugins like mcMMO or MachinaCraft more compatbile with NoCheatPlus. Not all existing plugins are covered (yet), but you can leave a note or create an issue/ticket request for cncp. Phasing out: Citizens 2 should work with NCP out of the box, MagicSpells are working on compatibility too - rest will be integrated into NCP.
Orebfuscator
Orebfuscator fights all sorts of X-ray-hacks by altering the map information that is sent to the players, such that they have to mine blocks to actually reveal what is behind. Virtually a "must have". (Latest versions of Spigot contain features of Orebfuscator.)
Downloads and History of Changes
- Download officially approved versions on the Files page at BukkitDev.
- Development builds have been moved over to the Jenkins at md-5.net.
- Do not download from any other source, do not use jars other people send you.
- Change lists: Wiki (digest) | Jenkins (by build number) | GitHub (all commits).
- Source code
Plugin statistics are no longer reported to mcstats.org.
Support
Documentation Resources
- Consider first: Frequently asked Questions and Known Issues.
- Wiki (Configuration, Permissions, Commands)
- Developers might have a look at the page describing the API of NoCheatPlus.
Contact us
- Quick questions can be asked on this page,
or on IRC (Server: irc.spi.gt | Default-Port: 6667 | SSL-Port: 6697 | Channel: #nocheat | Web client: WebIRC) - For real issues or feature requests please create a new issue/ticket or add to an existing issue/ticket.
- To send information that is not to be seen by all, you can also reach us by PM to @asofold and @MyPictures. @IceAP (IRC: ICE) will also help or redirect the conversation. Please do not contact the user 'NoCheatPlus', it is for administrative purposes only and will likely not be answered in time. Keep to BukkitDev and GitHub for support, do not trust users on other forums or websites, also not if their nick names are the same as NCP staff on BukkitDev.
Please always state the output of the "ncp version" command to let us know versions in use (users of cncp also the "cncp" command).
Comments
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_ForgeUser9668734 Owner
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_ForgeUser15078623 Ticket Manager
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_ForgeUser16101223 Contributor
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_ForgeUser7091862 Former Author
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_ForgeUser7459264 Former Author
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Forge_User_61842651 Author
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MyPicturesCP Artist
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Posted Dec 28, 2012I've got the same problem as others do on my server. Some people are unable to hit other players or move any items in their inventory. I'm not sure what causes this, and relogging fixes the problem.
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Posted Dec 28, 2012Concerning files linked by third people: I hope everybody is as "well-ionformed" as to never download jars from third people, especially from unknown sources. We have the Bukkit-staff-approved downloads here on BukkitDev and we have the jenkins (disregarding GitHub for the moment). Any other sources you download from at your own risk, and in general one should assume it to be malicious files, unless you really know otherwise. Of course there are people that are able to provide altered versions and whom one might trust, but you really have to know them and their intents. Never download from unknown sources.
Concerning problems with mobs/attacking: You can disable the anti-bot components with the combined.improbable and the combined.yawrate sections in the configuration. Of course you will allow force-fields to be much more efficient that way. I will try to bring in some improvements soon.
@MyPictures Thanks.
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Posted Dec 28, 2012I'm also seeing the issue where players are unable to attack mobs. They end up being helpless and getting killed from mobs because they can't do any damage to them. I can't imagine anyone with NoCheatPlus isn't seeing this issue. I would make a ticket, but it appears the "block place" ticket might be a similar issue.
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Posted Dec 28, 2012@zSwayz
Do you crash also? If yes could you give us a crash log from the client? Need more info's about that crash.... Normally NC+ shouldn't crash any vanilla client, it could crash a client that uses nuker (event overload) but for normal players it shouldn't do anything that could crash them. Also enabling plugins over this PlugMan could also bring up some strange behavior.
@noxturno
Thanks I will take a look at this as soon as I got enough time to do.
@herpingdo
Please don't post modified NC+ versions in the comments, if you want to fix something then make a pull request on github or just make a ticket on our dev.bukkit page.
Also 271 wont work on CB 2512 and up, we already updated NC+ to work with 1.4.6: http://dev.bukkit.org/server-mods/nocheatplus/files/42-nocheat-plus-3-8-7-beta-b294/
Latest builds you can always get from our Jenkins: http://nocheatplus.org:8080/job/NoCheatPlus/
(Deleted your post for now since we don't have enough time to decompile and check your work there)
@noxturno
What check shows up if they fail to hit a mob/player now?
@YoFuzzy3
Ok, thank you :)
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Posted Dec 28, 2012@asofold
Ah I did a timings check and it turns out that the lag was being caused by another plugin.
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Posted Dec 27, 2012Can you add censorship to the anti spam? You could use cuss words per minute as a way to detect spam or something.
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Posted Dec 27, 2012@asofold
Issue is still apparent with combined.improbable completely disabled.
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Posted Dec 27, 2012you can recreate this very easily by spawning lots of mobs and just punch them none stop after a few you will be unable to do any damage to mobs and you wont be able to place any blocks or even move your items in your inventory around. i disabled improvable thing on the config and it removes the issue but my players are taking random damage out of nowhere I cant seem to find the issue but my suspicions tell me is nocheat :(
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Posted Dec 27, 2012Having a lot of players clients crashing after re-enabling NoCheatPlus on my server. :<
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Posted Dec 27, 2012@wra1ths
It can happen, seemingly. What you could try is to raise the level for combined.improbable. I will try to add something to reduce penalty of more wild clicking.
Still you have to make sure the players are actually legit, an indication can be "/ncp info PLAYER" showing a wider range of violations. Especially with multiple mobs the improbable and yawrate checks will be quite effective against force fields, unfortunately they can also block players fighting mobs, if you have a grinder for instance, because you then reach "hilarious" average hit-rates and frequency. If you use TestNCP, yawrate cancels silently and might punish "wild" clicking, but will prevent attacks for not too long time. The improbable check keeps track of roughly 30 seconds, thus could block for a longer time, but would also lead to TestNCP / violations output in every single case.
@FourDowning
Difficult to judge, could be a memory leak, could be NCP could be CB/Spigot/plugins... if you have a big server, you might consider activating the data removal feature, though it also removes setback positions, allowing for more potential exploits.
Other topic: Do you restart once or twice per day? I would not even trust vanilla to run longer than 12 hours, but there may be other opinions...
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Posted Dec 27, 2012To add to the discussion of players not being able to hit mobs, the problem seems to occur when players are engaging large groups of mobs (>7-8) but not when going after single or small groups. Happens consistently with any large group, whether players are farming or just hunting. We've confirmed the issue is related to NCP on a test server (issue occurs while NCP is enabled, but not while just running vanilla). Our next step is seeing if we can get any more useful information out of TestNCP.
What we're running:
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Posted Dec 27, 2012@asofold I don't, but it builds up over time and then the lag spikes start. Sorry :(
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Posted Dec 27, 2012When I use it it wont load the plugin
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Posted Dec 27, 2012@Dominykasbc
Yes, you can disable it globally (logging.ingamechat), or for individual checks/vls (see configuration link on top of the page).
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Posted Dec 27, 2012Is it possible to disable notifications in server chat ?
NCP: daemondas failed FastBreak: tried to break blocks (13) faster than possible. VL 1.
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Posted Dec 27, 2012@Velanoris
Use the beta of NoCheatPlus: http://dev.bukkit.org/server-mods/nocheatplus/files/42-nocheat-plus-3-8-7-beta-b294/
You have that version already?
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Posted Dec 27, 2012@MyPictures
And the problem is that NoCheatPlus is not giving me any hacking notifications and it is allowing everyone to hack
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Posted Dec 27, 2012@MyPictures
I have the most recent version of craft bukkit along with the most recent version of NC+
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Posted Dec 27, 2012@FourDowning
It is december :) - what to look at? Any specific guess / info ?
@Puremin0rez
I'd prefer a crash log(ticket :) ) - i will review the metrics for other reasons anyway, so i put more consistency checking on the list. Just because the server crashes during processing of those, does not necessarily mean it is caused by it - do you happen to have any more info/logs on it ?
@bob7l
As @noxturno said, first make sure to test without being op and without having the checks bypass permissions.
@noxturno
@Puremin0rez
So both of you are using the latest beta of NCP (build 294)? How many players are affected ? What situations does this happen with (mob grinding, normal hunting, pvp)?
I will certainly attempt to improve the situation on this, still some cases have to be ruled out.
@YoFuzzy3
Does that happen without NCP as well (if you should have been able to test it, you might also disable the check for testing)?
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Posted Dec 27, 2012NoCheatPlus is causing a lot of lag in PvP. With just a few people attacking each other my server's TPS drops to 17-18 and the lag is very noticeable. I'm using CompatNoCheatPlus as well, could that be something to do with it?