• Guests logging in from "shell" as their location

    From Nightfox@1:103/705 to All on Sat Jul 15 12:17:44 2017
    Re: Guests logging in from "shell" as their location
    By: Nightfox to All on Fri Jun 16 2017 12:50 pm

    Recently I've noticed a lot of Guest logins on my BBS
    with the location specified as "shell" or "sh". They don't seem to be doing any harm, but I'm wondering if there might be any cause for concern? It seems they might be trying to run a command shell ('sh' etc.) to gain access, but that's just going into the location prompt during login, so I

    I've updated my logon script so that if anyone loggs in as Guest and using 'sh' or 'shell' as their real name/location, their IP address will be added to ip.can.

    Additionally, if anyone logs in as Guest and used 'sh' or 'shell', I wonder if I could have my logon script disable their system somehow (to stop them from attacking other systems) or at least do something annoying, like outputting a bunch of random ASCII characters or something.. Good idea or bad idea? Perhaps just adding their IP to ip.can would be far enough..

    Nightfox

    ---
    * Synchronet * Digital Distortion: digitaldistortionbbs.com
    * Origin: Vertrauen - vert.synchro.net (1:103/705)
  • From mark lewis@1:3634/12.73 to Nightfox on Sat Jul 15 15:55:22 2017

    On 2017 Jul 15 12:17:44, you wrote to All:

    Additionally, if anyone logs in as Guest and used 'sh' or 'shell', I wonder if I could have my logon script disable their system somehow
    (to stop them from attacking other systems) or at least do something annoying, like outputting a bunch of random ASCII characters or something.. Good idea or bad idea?

    bad idea... you cannot easily feed stuff back through their code that's running
    and hacking back on their system is most likely against the law in your area...

    Perhaps just adding their IP to ip.can would be far enough..

    that's the best thing...

    )\/(ark

    Always Mount a Scratch Monkey
    Do you manage your own servers? If you are not running an IDS/IPS yer doin' it wrong...
    ... And just how would you know where duck farts go underwater, young man?
    ---
    * Origin: (1:3634/12.73)
  • From KK4QBN@1:103/705 to mark lewis on Sat Jul 15 23:35:22 2017
    Re: Guests logging in from "shell" as their location
    By: mark lewis to Nightfox on Sat Jul 15 2017 15:55:22

    bad idea... you cannot easily feed stuff back through their code that's running
    and hacking back on their system is most likely against the law in your area...

    I always wanted to try to send an ansi bomb or something.. depending on what device it is.. like rokus can be remotely controlled via telnet anyway.. or at least send the ownwer of the IOT device a message telling them their device has been compromised..

    because yeah.. most of the people who are hosting these bots have the slightest idea that they are dong it.

    --

    Tim Smith (KK4QBN)
    KK4QBN BBS

    ---
    * Synchronet * KK4QBN - kk4qbn.synchro.net - 7064229538 - Chatsworth GA USA
    * Origin: Vertrauen - vert.synchro.net (1:103/705)
  • From Lith@1:103/705 to Nightfox on Sat Jul 15 18:45:40 2017
    I've updated my logon script so that if anyone loggs in as Guest and using 'sh' or 'shell' as their real name/location, their IP > address will be added to ip.can.

    Can we get a copy of this script?

    Also, I'm not a programmer, but I was thinking the initial telnet connect challenge (captcha) code idea would be better because it would automatically stop "all" automated bots without using an ip.can. You can see it on A2K BBS. Example below:

    ----------------------------
    Code: 12345
    Enter the above code above to proceed:
    --------------------------------

    Lith,

    ---
    * Synchronet * www.asirta.com + Retro Music / Games / Gear + radio.asirta.com
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  • From Nightfox@1:103/705 to Lith on Sat Jul 15 23:26:00 2017
    Re: Guests logging in from "shell" as their location
    By: Lith to Nightfox on Sat Jul 15 2017 06:45 pm

    I've updated my logon script so that if anyone loggs in as Guest and
    using 'sh' or 'shell' as their real name/location, their IP > address
    will be added to ip.can.

    Can we get a copy of this script?

    Well my logon script has other customizations in it that are specific to my BBS.. It won't all work for another BBS if I share it as it is. The part that checks for the guest/shell login was not too complicated anyway.. It's in login.js in the section that checks for UFLAG_G (the guest account), after they enter their email address & location, it checks if they entered "shell" for either of those
    and if so, it just calls system.filter_ip() to add the IP address to ip.can.

    Nightfox

    ---
    * Synchronet * Digital Distortion: digitaldistortionbbs.com
    * Origin: Vertrauen - vert.synchro.net (1:103/705)
  • From KK4QBN@1:103/705 to Lith on Sun Jul 16 13:12:40 2017
    Re: Guests logging in from "shell" as their location
    By: Lith to Nightfox on Sat Jul 15 2017 18:45:40

    see it on A2K BBS. Example below:

    ----------------------------
    Code: 12345
    Enter the above code above to proceed:
    --------------------------------


    you can stop most of them by putting a simple "Press ENTER" prmpt before yo ask for login info..

    the bot will automaticially send UN/PW at the PRESS ENTER prompt.. so only password gets sent to username.. so even if they are using GUEST.. they still cannot get in.

    They don't worry me a bit.. just a bit of a nuisance..

    --

    Tim Smith (KK4QBN)
    KK4QBN BBS

    ---
    * Synchronet * KK4QBN - kk4qbn.synchro.net - 7064229538 - Chatsworth GA USA
    * Origin: Vertrauen - vert.synchro.net (1:103/705)
  • From Denn Gray@1:103/705 to KK4QBN on Sun Jul 16 14:24:46 2017
    Re: Guests logging in from "shell" as their location
    By: KK4QBN to mark lewis on Sat Jul 15 2017 11:35 pm

    I always wanted to try to send an ansi bomb or something.. depending on what device it is.. like rokus can be remotely controlled via telnet anyway.. or at least send the ownwer of the IOT device a message telling them their device has been compromised..


    that gave me an idea that I just implemented on the outwest BBS,
    When these annoying bots keep trying to log onto my system and get blocked now they get greeted with 1,000 lines of a random text bomb, I went to a site called random.org and had it create my 1,000 lines of random text, then I cut and pasted that into my badip.can file, I then put my ip in the ip.can file to test it, it's pretty funny to get bombed by all those lines of text and the system actually drops the connection before all the text is displayed.

    "... Press any key to continue or any other key to quit"

    ---
    * Synchronet * the Outwest BBS - outwestbbs.com Telnet - outwestbbs.com:23
    * Origin: Vertrauen - vert.synchro.net (1:103/705)
  • From Nightfox@1:103/705 to KK4QBN on Mon Jul 17 09:39:02 2017
    Re: Guests logging in from "shell" as their location
    By: KK4QBN to Lith on Sun Jul 16 2017 01:12 pm

    you can stop most of them by putting a simple "Press ENTER" prmpt before yo ask for login info..

    the bot will automaticially send UN/PW at the PRESS ENTER prompt.. so only password gets sent to username.. so even if they are using GUEST.. they still cannot get in.

    They don't worry me a bit.. just a bit of a nuisance..

    Yeah, it doesn't bother me a whole lot.. I put up a captcha input for the guest login, but I'm not sure if that's necessary, or to just detect that they entered "shell" and hang up on them. I suppose the captcha is a more generic solution.

    It doesn't really worry me much either.. Actually the thing that bugs me the most is that even if they don't continue the login process, Synchronet still seems to record a login with the guest account. So, some days it might report that I got a bunch of logins, but most of them were the guest/shell attempts..

    Nightfox

    ---
    * Synchronet * Digital Distortion: digitaldistortionbbs.com
    * Origin: Vertrauen - vert.synchro.net (1:103/705)
  • From Nightfox@1:103/705 to Denn Gray on Mon Jul 17 09:40:56 2017
    Re: Guests logging in from "shell" as their location
    By: Denn Gray to KK4QBN on Sun Jul 16 2017 02:24 pm

    that gave me an idea that I just implemented on the outwest BBS,
    When these annoying bots keep trying to log onto my system and get blocked now they get greeted with 1,000 lines of a random text bomb, I went to a site called random.org and had it create my 1,000 lines of random text, then I cut and pasted that into my badip.can file, I then put my ip in the ip.can file to test it, it's pretty funny to get bombed by all those lines of text and the system actually drops the connection before all the text is displayed.

    I was thinking of modifying my login script so that if someone logs in with Guest and "shell", it would send a bunch of random text, but as someone pointed out, hacking back could be considered illegal where you live..

    Nightfox

    ---
    * Synchronet * Digital Distortion: digitaldistortionbbs.com
    * Origin: Vertrauen - vert.synchro.net (1:103/705)
  • From Nightfox@1:103/705 to All on Fri Jun 16 12:50:10 2017
    I thought I saw some recent posts regarding this on Dove-Net, but now I don't see them.. Recently I've noticed a lot of Guest logins on my BBS with the location specified as "shell" or "sh". They don't seem to be doing any harm, but I'm wondering if there might be any cause for concern? It seems they might be trying to run a command shell ('sh' etc.) to gain access, but that's just going into the location prompt during login, so I don't think it's going to do anything harmful. I've never seen any bots doing this until recently though. My BBS has been getting a lot of these Guest/shell logins lately, from many different IP addresses.

    Users specifically have to know they can log in as Guest, which makes me wonder if people are starting to write attack scripts for Synchronet BBSes? I'm also using a login matrix with a lightbar menu, so people would have to specifically choose the option from the menu to use a guest account.. Unless they don't have ANSI, in which my BBS should revert to a more plain text login.

    I even got a message from the Guest account recently where someone asked me how to create a new user account. This makes me think there may be something more than dumb scripts attacking BBSes now.

    Nightfox

    ---
    * Synchronet * Digital Distortion: digitaldistortionbbs.com
    * Origin: Vertrauen - vert.synchro.net (1:103/705)
  • From KK4QBN@1:103/705 to Nightfox on Fri Jun 16 18:23:06 2017
    Re: Guests logging in from "shell" as their location
    By: Nightfox to All on Fri Jun 16 2017 12:50:10

    I thought I saw some recent posts regarding this on Dove-Net, but now I don't see them.. Recently I've noticed a lot of Guest logins on my BBS with the location specified as "shell" or "sh". They don't seem to be doing any harm, but I'm wondering if there might be any cause for concern? It seems they might be trying to run a command shell ('sh' etc.) to gain access, but that's just going into the location prompt during login, so I don't think it's going to do anything harmful. I've never seen any bots doing this until recently though. My BBS has been getting a lot of these Guest/shell logins lately, from many different IP addresses.

    it is the Mirai bot, it gains access using the guest username, and sh, shell, admin, and other "popular" usernames are also passed and just happen to fill the field of "what is your location" question on guest sighn in.

    all of these attempts I've seen try to pass 4 or 5 usernames, then just give up, I presume when whatever these bots are looking for is not found.

    Mirai does'nt know of BBS systems obviously, and hoepfully no one will decide that it should.



    --

    Tim Smith (KK4QBN)
    KK4QBN BBS

    ---
    * Synchronet * KK4QBN + (706)-422-9538 + kk4qbn.synchro.net + 24/7/365
    * Origin: Vertrauen - vert.synchro.net (1:103/705)
  • From mark lewis@1:3634/12.73 to Nightfox on Fri Jun 16 18:57:00 2017

    On 2017 Jun 16 12:50:10, you wrote to All:

    Users specifically have to know they can log in as Guest, which makes
    me wonder if people are starting to write attack scripts for
    Synchronet BBSes?

    it ain't nothing like that at all... it is, still, the MIRAI botnets trying to conscript your BBS into the botnet... they're trying a list of names and passwords... they don't care what output your system is spitting at them... they emit a username, a password, and then a specific string of commands which generally terminates with "MIRAI" or one of the other variant signatures...


    )\/(ark

    Always Mount a Scratch Monkey
    Do you manage your own servers? If you are not running an IDS/IPS yer doin' it wrong...
    ... Tune in, turn on, and be friends with EX-Mayor Barry.
    ---
    * Origin: (1:3634/12.73)
  • From mark lewis@1:3634/12.73 to KK4QBN on Fri Jun 16 19:15:04 2017

    On 2017 Jun 16 18:23:06, you wrote to Nightfox:

    it is the Mirai bot, it gains access using the guest username, and sh, shell, admin, and other "popular" usernames are also passed and just happen to fill the field of "what is your location" question on guest sighn in.

    those are not all usernames... only the first one is a username... the second in the sequence is the password they're trying for that name... everything else
    is shell commands they're trying to use to gain a foothold in the device... it sounds like you have your system set to ask guests for their location when they
    login...

    here's an example of what a complete MIRAI login attempt emits...

    1. username<crlf>
    2. password<crlf>
    3. enable<null><crlf>
    4. system<null><crlf>
    5. shell<null><crlf>
    6. sh<null><crlf>
    7. /bin/busybox SIGNATURE<null><crlf>

    numbers 1 and 2 are each from a limited list and will generally be different for each attempt... numbers 3 thru 6 are always the same... number 7 is the same, too, except for the "SIGNATURE" part which may be one of numerous signatures... signatures which can be used to determine a variant of MIRAI... the initial signature was, of course, MIRAI but there are at least 12 known variants that use another phrase or character sequence... OBJPRN, FREEPEIN, CIA, FBI, WHOSGHOST, and others...

    there are some that use another sequence similar to the above... everything is the same as above but then they are trying tftp or wget commands at or after number 7... some are also using echo and printf commands to try to determine the system they are connected to and what capabilities they may have access to...

    the list of usernames and passwords is pretty short... one would do good to add
    those to their .can files, for one thing... another would be to follow the wiki
    page concerning hackers and to tighten up their system's login timing stuff along with allowing sbbs to add the IP to the ip.can to prevent further incurcions from that IP...

    all of these attempts I've seen try to pass 4 or 5 usernames, then
    just give up, I presume when whatever these bots are looking for is
    not found.

    they're looking for a specific response to their command init string... it gets
    recorded for a later visit which will implant the rest of the MIRAI worm...

    Mirai does'nt know of BBS systems obviously, and hoepfully no one will decide that it should.

    it won't do them any good if it did... there's too much variation between systems for them to be able to do anything worthwhile ;)

    )\/(ark

    Always Mount a Scratch Monkey
    Do you manage your own servers? If you are not running an IDS/IPS yer doin' it wrong...
    ... "Transporter chief Scott, beam @N@ to the bridge." ;*)
    ---
    * Origin: (1:3634/12.73)
  • From KK4QBN@1:103/705 to mark lewis on Fri Jun 16 23:23:16 2017
    Re: Guests logging in from "shell" as their location
    By: mark lewis to KK4QBN on Fri Jun 16 2017 19:15:04

    Mirai does'nt know of BBS systems obviously, and hoepfully no one
    will decide that it should.

    it won't do them any good if it did... there's too much variation between systems for them to be able to do anything worthwhile ;)

    Thats pretty much what I was thinking too.. I did notice that something (not using any Mirai signature) but acting just like it gained access with the guest account and posted something on my postit wall that is in my login sequence before it went away. strangest thing I have seen, let me try to find the message.

    " Guest@1496840074
    i like memes^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?Adolfcoin is a great investment^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^?^ ?^?^?^?^?^?^^^FGass^? the jews
    14/88"

    This is a new one on me, I tracked the IP from this particular login time, and this is not a human, it acts just as Mirai does.

    --

    Tim Smith (KK4QBN)
    KK4QBN BBS

    ---
    * Synchronet * KK4QBN + (706)-422-9538 + kk4qbn.synchro.net + 24/7/365
    * Origin: Vertrauen - vert.synchro.net (1:103/705)
  • From Digital Man@1:103/705 to Nightfox on Fri Jun 16 23:49:56 2017
    Re: Guests logging in from "shell" as their location
    By: Nightfox to All on Fri Jun 16 2017 12:50 pm

    I thought I saw some recent posts regarding this on Dove-Net, but now I don't see them.. Recently I've noticed a lot of Guest logins on my BBS with the location specified as "shell" or "sh". They don't seem to be doing any harm, but I'm wondering if there might be any cause for concern? It seems they might be trying to run a command shell ('sh' etc.) to gain access, but that's just going into the location prompt during login, so I don't think it's going to do anything harmful. I've never seen any bots doing this until recently though. My BBS has been getting a lot of these Guest/shell logins lately, from many different IP addresses.

    Users specifically have to know they can log in as Guest, which makes me wonder if people are starting to write attack scripts for Synchronet BBSes?

    Doubt it. "Guest" is not that unusual of a user name. Perhaps it's just one of the guesses in their userid/password database.

    I'm also using a login matrix with a lightbar menu, so people would have to specifically choose the option from the menu to use a guest account..
    Unless they don't have ANSI, in which my BBS should revert to a more plain text login.

    It's likely that the scripts don't support ANSI. :-)

    digital man

    Synchronet/BBS Terminology Definition #21:
    FF = Form Feed (ASCII 12, Ctrl-L)
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  • From Denn Gray@1:103/705 to KK4QBN on Sat Jun 17 07:00:44 2017
    Re: Guests logging in from "shell" as their location
    By: KK4QBN to Nightfox on Fri Jun 16 2017 06:23 pm

    it is the Mirai bot, it gains access using the guest username, and sh, shell, admin, and other "popular" usernames are also passed and just happen to fill the field of "what is your location" question on guest sighn in.

    all of these attempts I've seen try to pass 4 or 5 usernames, then just give up, I presume when whatever these bots are looking for is not found.

    Mirai does'nt know of BBS systems obviously, and hoepfully no one will decide that it should.

    Even if they got to stage 2 of the sign in it is doubtful they could get any further, The worst offenders i.e. the ip's that try over and over to gain access to my BBS get put in the ip.can.
    My BBS is run on a single machine with port forwarding to the ports it needs, all other ports are blocked by my router.
    I also limit logins to 2 nodes at a time so they can't down all my nodes.
    I believe these bots are expecting a unix or linux os and try to gain root access.

    ---
    * Synchronet * the Outwest BBS - outwestbbs.com
    * Origin: Vertrauen - vert.synchro.net (1:103/705)
  • From Nightfox@1:103/705 to Digital Man on Mon Jun 19 09:07:34 2017
    Re: Guests logging in from "shell" as their location
    By: Digital Man to Nightfox on Fri Jun 16 2017 11:49 pm

    Doubt it. "Guest" is not that unusual of a user name. Perhaps it's just one of the guesses in their userid/password database.

    I wondered about that..

    It's likely that the scripts don't support ANSI. :-)

    I figured that was probably the case. :)

    Nightfox

    ---
    * Synchronet * Digital Distortion: digitaldistortionbbs.com
    * Origin: Vertrauen - vert.synchro.net (1:103/705)