How to protect your network from Skype

Skype Skype (IP) and Internet Calling (IP) applications, from where no one is known, now have about 150 million users with 6 million people online online in just 3 years. And inevitably the usual rule, Skype is subjected to many vandalism, looking for ways to infiltrate. Some security issues appear, especially when Skype is used in large enterprise networks.

In many people's perception, Skype may be a security hole, allowing hackers to take advantage of it to penetrate the system. They also claim that it encrypts all communications so the sending process cannot be monitored, or Skype uses too much network bandwidth and transmits dangerous files.

Skype is not easy to manage. But if you're worried about Skype being used on your network, there are many methods to help you remove or make sure it's safe. Let's see if you can protect your network and Skype users from the dangers it brings.

Find Skype users online

The first thing to do is find out who is using Skype on your network. If you have one of the network configuration management application programs such as Microsoft SMS, LANDesk HP or OpenView Client Configuration Manager, you have enough tools in hand. Use built-in functions within those applications.

If there is no such application, don't worry. Download a sample script named Skype_Check for Windows on the SkypeTips.com website and take the following steps:

• Check whether Skype is installed on the computers in the network and make a report of the systems that have it.
• Record the version of Skype.
• Check to see if any proxy is set for it.
• Check the Skype port you are using and record it.
• Check if port 80 is allowed to use and record.
• Checking the port is in use and allows you to copy Shared XML files with the correct settings.
• Check and interrupt file transfer, record.
• Check and interrupt Skype API, record.

You can use your login script to search for files running Skype.exe; or use a script and execute it on the IP address scheme, assign each client with the appropriate admin account, Skype search and any existing XML or registry settings. And, of course, you can also use a configuration management application as mentioned above, or use a combination of scripts and configuration management applications, depending on what you need, record, manage , blocking or deleting Skype.

Remove Skype

If you decide to ban Skype from circulating on your network, you can do so in a number of ways. The simplest is to 'scour' and delete all copies of Skype on each computer in the network. You will need a GUI tool to search and destroy Skype. A free utility called SkypeKiller allows you to browse the network, record a list of Skype machines and then delete them from those machines. SkypeKiller also allows you to schedule removal programs. With the current machines not online, it will perform its work automatically the next time, when those machines go online.

You want to make sure that users cannot download and install Skype, use the network management tool to remove network access to the website www.skype.com. Not enough, because users can always get this software anywhere. Prevent Skype from installing on the system using Group Policy Active Directory options or remove user administration privileges. You can also use the configuration management application to remove Skype and record it when Skype is found during the listing review process.

In addition, you can run a test program when users log in or use scripts to search and delete Skype. You can download and use the Skype_Delete for Windows script on the Web site.

Remote users are the biggest challenge for administrators, because they are not connected to the local network on a regular basis. So, how to manage remote users or delete Skype on their computers?

If you have a configuration management application, use it with the 'home phone' agent when the computer is connected to a virtual private network (VPN). Then use VPN quarantine functions.

You may want to wait after the user logs in to the local network to use a login script to 'grab' them. But many users use laptops, and rarely connect to local networks. To solve this problem, you can add Skype to the virtual private network login policy to determine if Skype is used. Then delete them when users log on to the VPN network during the process of checking their personal firewall and anti-virus software.

Remove Skype with Windows XP firewall (Service Pack 2)

If you are using Windows XP Service Pack 2 and Windows firewall, there is a Microsoft utility provided to control a firewall called netsh. You can use the nesh command to remove Skype from the list of provided applications, or change the rules so that Skype uses a fake IP address. Do as follows:

netsh firewall set allowedprogram C: progra ~ 1Skypephoneskype.exe Skype disable

netsh firewall set allowedprogram C: progra ~ 1Skypephoneskype.exe Skype enable custom 10.1.2.3

Eliminate Skype at the network layer

So far, we have discussed removing or deleting Skype on the client layer. But reality requires more comprehensive solutions for large corporations and companies that need high security. One of them is the application that removes network IM and Skype. These hardware applications are configured to identify the specific protocols used for programs such as Skype, and then remove their network traffic. Such software is quite expensive, so it is not suitable for small businesses. Some of them are Verso, Ipoque, Lynanda, SonicWall, Packeteer .

If you are using a proxy server like Squid for all Web access, you can configure this proxy to eliminate Skype and IM related requests. Just search on Google with the keyword 'Skype AND Squid', you will have a lot of information about it.

Manage Skype settings

What if you decide to allow users to use Skype, but want to manage the settings on all PCs on the network? You can use Active Directory Group Policy or a configuration management application or scripts like some of the examples I mentioned above. You can control Skype's activities such as preventing the system from becoming a Supernode, disabling the file transfer process, controlling which ports and protocols Skype is used and some other settings. If you want a complete list of Skype settings, you can look at the Skype's Guide for Network Admins.

Finally, if you want to monitor Skype on user systems, use the Windows login script to run a test program when a user logs in to the system, or run 'Run Key' on a laptop and record what you have searching.