How to block VPN apps?

Hi all,

I have a XG 550. I would like to block VPN apps like X-VPN, UltraVPN or something like that.
I created an application filter policy following this guide https://community.sophos.com/kb/en-us/123108

I also block all proxy and VPN app listed in Application Filter Criteria.

But user still can use X-VPN to bypass the XG.
My XG running 16.05.8.

Please give me some advice.
Thank you.

  • Hi ,

    I shall try to re-create this issue and update this thread.

  • Create an Application Filter policy with below details :

     

    1. Block 'Proxy and Tunnel' category.

    2. Block Category - Category = ALL except Proxy and Tunnel, Characteristics = Can bypass firewall policy.

    3. Block 'DNS Multiple QNAME'.

     

    Web Filter - Block Anonymizers, Peere-to-Peer on HTTP, HTTPS.

     

    Create a Test rule on top for one machine and apply this. Keep on top of even DNS rule. 

     

    If it doesn't work, go to console and increase max packets to 100.

    set ips maxpkts 100

     

    Let us know if it works.

     

  • In reply to Anish Deval:

    Thanks for your advice.
    I did it but it won't help. It can block other VPN apps like FastVPN, UltraVPN but can't block X-VPN.
    I see that X-VPN use 7 protocols. After adjusting the policy following your instruction, XG just block 2 of those 7. And then X-VPN connected with the 3rd protocol. 

  • In reply to The Do:

    I am also facing this challenge to block X-VPN.

    There hasn't been any further updates on how to completely block X-VPN, any further suggestions on how to permanently block this VPN?

     

    Thanks kindly,

  • In reply to Liz Gipson:

    Protocol C and E will still be blocked because they use TLS  TCP 443. I reversed the app and saw it creating a local host. You can find this by opening x-Vpn on Mac and visiting 127.0.0.1:4001. Also, I have detected that blocking IP addresses does not work due to its multi hop technology. I know the dns is 114.114.114.114 if that helps. Contact me or reply if you need more info.

  • In reply to Taher Ismail:

    Has anyone thought of telling your employees that using this application is against company policy and they will be sacked.

    Please apply some commonsense here, firewall can fo many things but not overcome human stupidity, like putting the business at risk by using unsecured applications.

    Ian

  • In reply to rfcat_vk:

    Hey,

    I’m actually a student 16, I have partnered up with school (sort of employed) in order to block this VPN at school.

  • In reply to Taher Ismail:

    Hi,

    the school really should employ a specialist consultant. I am not doubting your ability or experience or even your future business skills.

    Does the school have https scanning enabled? Does the school use or allow google apps and other search engines. Do you have enforce safe search enabled?

    Reading about X-VPN shows it uses a lot of search engine functions, so by blocking advertisements etc might help?

    Ian

  • In reply to rfcat_vk:

    Hey, our school has employed a number of security and IT specialists. They work with a company called Linewise which claims to filter SSL and HTTPS. They are unable to block X-VPN. Also let me know if SkyVPN and Psiphon VPN work on your network.

    School needs to allow google apps because most of our learning is based around school. X-VPN uses api URLs such as 8v9m.com and tubnet.com I can provide a list if needed as giving this to my IT hasn’t really resulted in any success. Safe search is enabled.

    Even deompliling their iOS app, android app and their Mac and chrome extension, I was able to find a premium server list. Blocking IPs don’t even work and since using their method called pretendauthtls they work similar to openvpn ssl meaning it is difficult to detect.

  • In reply to Taher Ismail:

    Hi,

    I have been experimenting with my firewall rules.

    You  need a two pronged approach:-

    1/. web filter rule - xvpn.io and x-vpn.io deny

    2/. you need an application rule blocking proxy and tunnel as well as p2p sites.

     

    If you need specifics I will copy my rules for you. Mind you I think I have broken neighbours work tunnel. I will build a new set application rues for my specific access.

    Ian

  • In reply to Taher Ismail:

    Hi guys, thank you for your all comments. Actually I opened a ticket support. There were at least 3 technical joined that ticket. Finally I received the best answer from the senior technical:

    - We expect user machine having Sophos Secure certificate available and installed on user machine as this is require HTTPS scanning needs to be enable in firewall rule which is there and without this setting XG will not take action on application traffic.

    For reference, please follow below KB article for adding certificate on user machine.

    https://community.sophos.com/kb/en-us/123048

    - Goto Protect > Web > Protection > Click on Advance and Enable below settings.

    > Enable Pharming Protection.
    > Block unrecognized SSL protocols.

    It could help. But we must installed the certificate on all devices joining the network. Is it possible? And somehow that settings also made some troubles with other apps like Facebook or Whatsapp.

    In general, it is impossible to block X-VPN in the simplest way by Blocking X-VPN category. And if you block X-VPN in any cost, some other apps will get issue.

  • In reply to The Do:

    Hey, so this method will basically look for anything sent in the headers. If there is anything in the headers to suggest it is a vpn it will be blocked. This method is essentially a man in the middle attack and will break most https sites if they have certificate pinning.

    If it helps, x-Vpn is partly written in go and some of the files it “steals” it’s code from are from GitHub.

  • In reply to rfcat_vk:

    This is a client and they are using they are using x-vpn to get past all of the other rules. What they don't know is that we are aware of what they are doing... :D

  • In reply to The Do:

    Are you aware of what other apps will have issues?  As this is a corporate client I have to be careful what I am blocking!

    They have VPN connections set up to access the server from 4 different locations and run a couple of different programs on it.

    Thanks kindly!

  • In reply to Liz Gipson:

    In my case, facebook can't load the image, whatsapp on mobile can't connect.