Security Basics mailing list archives
Re: Blocking Instant Messaging Applications
From: Alloishus BeauMains <all0i5hu5 () gmail com>
Date: Mon, 21 Nov 2005 14:39:23 -0600
At the PIX or firewall, or wherever your ACLs are kept, block incoming or outgoing traffic to oscar.aol.com, the messenger login servers, trillian, yahoo, etc etc etc. You should be able to pull those from the connection logs. The clients initiate contact with those authentication services, and if they can't reach them, then they cannot logon and use them. Cleanest and easiest to me. If people cant logon to the service, then you have rendered it useless. On 11/21/05, Neksus <neksus () gmail com> wrote:
Jeremy, A solution that I implemented in the past (for MSN) is as follow: 1. Install a firewall, block everything that is a direct connection from the desktop. 2. Install a proxy for FTP, web and https (20/21/80/443). Only the proxy server should be allowed to directly connect to the internet. 3. Put the MSN domain name in your own DNS to prevent the application from reaching the server by hoping on port 80. I forgot what is the domain name off the top of my head. 4. Block access to the local hosts file to avoid clever users from adding the IP in the file (Windows will read this file first, then DNS). Users should not be admins of their own machine. 5. Install an internal server if you have a large user base (country wide or international). Microsoft has one that is easy to setup but you'll need to use Windows Messenger instead of MSN messenger. They also release Windows Communicator or something close that is Windows Messenger on steroids. 6. Relax and enjoy. There might be other ways. I'm just giving you my own recipe. (N)
Current thread:
- Blocking Instant Messaging Applications Gaddis, Jeremy L. (Nov 21)
- RE: Blocking Instant Messaging Applications Murad Talukdar (Nov 22)
- <Possible follow-ups>
- RE: Blocking Instant Messaging Applications Nick Duda (Nov 21)
- RE: Blocking Instant Messaging Applications Murad Talukdar (Nov 22)
- RE: Blocking Instant Messaging Applications Aditya Deshmukh (Nov 24)
- Re: Blocking Instant Messaging Applications Gaddis, Jeremy L. (Nov 22)
- RE: Blocking Instant Messaging Applications Murad Talukdar (Nov 22)
- Re: Blocking Instant Messaging Applications Neksus (Nov 21)
- Re: Blocking Instant Messaging Applications Alloishus BeauMains (Nov 22)
- Re: Blocking Instant Messaging Applications Gaddis, Jeremy L. (Nov 22)
- RE: Blocking Instant Messaging Applications Aditya Deshmukh (Nov 24)
- Re: Blocking Instant Messaging Applications Gaddis, Jeremy L. (Nov 22)
- RE: Blocking Instant Messaging Applications Alexis Villagra - VILSOL LatinAmerica (Nov 22)
- Re: Blocking Instant Messaging Applications Alloishus BeauMains (Nov 22)
- RE: Blocking Instant Messaging Applications Collier, Simon (Nov 22)
- RE: Blocking Instant Messaging Applications Aditya Deshmukh (Nov 24)
- RE: Blocking Instant Messaging Applications Hartmann (Nov 25)
- RE: Blocking Instant Messaging Applications Aditya Deshmukh (Nov 24)
- RE: Blocking Instant Messaging Applications Beauford, Jason (Nov 23)
- RE: Blocking Instant Messaging Applications Murad Talukdar (Nov 24)
- Re: Blocking Instant Messaging Applications Neksus (Nov 23)