How to Encrypt Your DNS for More Secure Browsing

We’ve been touting the benefits of third-party DNS servers for a while now, but one additional benefit that might be of interest is the ability to encrypt all of your DNS requests, further protecting you from anybody spying on you in the middle.

DNSCrypt, from the great team at OpenDNS, is the simple solution that we’ll use to add encryption between your computer and the DNS server. It’s a lightweight solution that works on either Windows or Mac — sadly no mobile support so far.

What this tool is actually doing is creating an encrypted connection to any of the supported DNS servers, and then creating a local DNS proxy on your PC. So when you try to open howtogeek.com, your browser will send a regular DNS query to the 127.0.0.1 localhost address on port 53, and that request will then be forwarded through the encrypted connection to the DNS server.

Denial-of-service Attack – DOS using hping3 with spoofed IP in Linux

In computing, a denial-of-service (DoS) or distributed denial-of-service (DDoS) attack is an attempt to make a machine or network resource unavailable to its intended users.

Although the means to carry out, the motives for, and targets of a DoS attack vary, it generally consists of efforts to temporarily or indefinitely interrupt or suspend services of a host connected to the Internet.
As clarification, distributed denial-of-service attacks are sent by two or more persons, or bots, and denial-of-service attacks are sent by one person or system. As of 2014, the frequency of recognized DDoS attacks had reached an average rate of 28 per hour.
Perpetrators of DoS attacks typically target sites or services hosted on high-profile web servers such as banks, credit card payment gateways, and even root nameservers.
Denial-of-service threats are also common in business, and are sometimes responsible for website attacks.

Advanced Networking Commands

In one of our previous tutorials, you've learned how to use basic commands in Command Prompt. Now it's time to take things to the next level and show how to use some of the more advanced commands. The first set of advanced commands contains useful network commands which facilitate the following: viewing information about your network devices and connections (assigned IP Address, the MAC of the network card), checking the availability of a certain host and displaying a wealth of networking and ports information

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Retrieving Information about Your Network Connection

To obtain detailed information about your network connection, use the ipconfig command. Type ipconfig in Command Prompt and press Enter. As you can see below, a list with the network devices existing on your system and their IP addresses is displayed. You get also details such the default gateway, subnet mask or the state of the network adapter.

How to change the Terminal Services or Remote Desktop Port

Many organizations that use Remote Desktop Services or Terminal Services are not using a VPN connection before allowing connections to their in-house servers or workstations.  If no VPN is required, this means that the Terminal Server or Remote Desktop is publicly visible and allows connections from anyone on the network and in most cases the Internet.  This is a major security risk because it allows remote hackers to attempt to use password cracking attacks on your accessible servers in order to gain remote access. As Remote Desktop Services are configured by default to listen on TCP port 3389, all a hacker has to do is scan the Internet for computers that have that port open and then use a cracking program to try and crack the computer's accounts and passwords. This may seem like a hard task, but it is actually not difficult at all using free and publicly available tools.

The process is not only simple but pretty much automated for the hacker. They first use a port scanning tool to scan the Internet for IP addresses that have port 3389 open. They then load this list of IP addresses along with a custom or included user name and password list into the cracking software and let it run. This program runs until its done and then spits out a list of cracked accounts, passwords, and their associated IP addresses. The hacker then takes this information, logs into the remote computers and does what they want, such as encrypting all your data and making you pay a ransom. As you can see, this process may be time consuming, but it's really not hard to do.

Therefore, by changing the port that Terminal Services or Remote Desktop Services listens on, your computer would not show up when they scan IP addresses for 3389. This significantly reduces your chances of having these services remotely hacked. It is not 100% foolproof and VPN services are much more secure, but it definitely goes a long way in securing your Terminal Server or Remote Desktop Server.

This tutorial will explain how to change the port that your Terminal Services or Remote Desktop Services listen on. It will also explain how connect to these services through the Remote Desktop Client using a custom port.

How to change the Terminal Server or Remote Desktop listening port

The port setting for Remote Desktop Services is found in the Windows Registry. In order to change this setting we will need to change the PortNumber value in the following key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp

WARNING: Before making any Registry modifications it always advisable to make a complete backup of your Windows Registry before proceeding. To do this, you can use the free ERUNT tool to easily and quickly make a complete backup of your Registry that you can restore in the event of an issue.

To change the port, click on the Windows Start button and type Regedit in the search field and then press Enter on your keyboard. If you are in Windows XP, you will have to click on the Run button before typing. Once you press enter, the Registry Editor screen will appear as shown below.

Windows Registry Editor

Navigate to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp key and when there left click once on the RDP-Tcp key in the left pane. In the right pane of the windows you will now be presented with a list of values that are under this key. Scroll down on the right until you see the PortNumber value as shown below.

PortNumber Value

Now double-click on the PortNumber value and you will be shown a small dialog where you can change its value. When the dialog opens, it will be configured to show you the hexadecimal equivalent of the port number. As it easier to use decimal numbers, select the Decimal radio selection under the Base category. The dialog box should now be similar to the one below.

Edit the PortNumber Value

Type the new port number that you would like to use instead of 3389 in the Value data field and then press the OK button. You can now close the Registry Editor program.

You now need to reboot your computer in order for the changes to go into effect.

Your Remote Desktop Services or Terminal Server is now configured to use the new port that you entered.

How to connect to a Terminal Server or Remote Desktop that is using a custom port

When you use the Remote Desktop Client to connect to a remote computer it will automatically attempt to make the connection on port 3389. If you are connecting to a computer that uses a custom Remote Desktop Services port you must specify the custom port as part of the address you are connecting to. To do this, you simply add a colon followed by the port number to the IP address or host name you are connecting to. For example, if you were connecting to the host rd.example.com and it used a custom port of 8178, you would need to specify example.com:8178 as the computer you are connecting to.

Examples of a Windows and Mac Remote Desktop Client connecting to a remote port are

Windows Remote Desktop Client

Mac Remote Desktop Client

As you can see in the above pictures, you specify the port as part of address by using a colon.

You should now know how to connect to a Terminal Server or Remote Desktop Server that is using a custom port.

Group Policy Object Modeling in Windows Server 2008

If you have ever done much work with group policies, then you have undoubtedly found out that managing group policies are an organization wide basis can be a complicated endeavor. That's primarily due to the hierarchical nature of group policies. Group policy settings can be applied at the OU, site, domain, and local computer levels. All of these various group policy objects combine to form the effective policy.

group policy objects were not enough, contradictory settings can, and often do exist within the various group policy objects. Not only can two separate group policy objects contained directly contradictory settings, the group policy settings that apply to the computer can sometimes also contradict with group policy settings applied to a user.

Windows has all kinds of rules for automatically dealing with contradictory group policy settings. Even so, you as an administrator need to know the outcome of these conflict resolutions and what the effective policy look like once the various policy elements have been combined. In Windows Server 2003 this was known as the resultant set of policy. In Windows Server 2008, Microsoft has changed the name to group policy modeling.

Why Do Group Policy Modeling?

There are several different reasons why you might want to engage in group policy modeling. For starters, even if everything appears to be running smoothly is a good idea to periodically use group policy modeling just to make sure that group policies are being applied in the way that you think that they are. Group policy modeling is also extremely useful in situations in which you are reorganizing the Active Directory or creating new group policy objects.

Performing Group Policy Modeling

To perform group policy modeling begin by opening the Group Policy Management Console. When the console opens, right-click on the Group Policy Modeling container and choose the Group Policy Modeling Wizard command from the shortcut menu. When you do, Windows will launch the Group Policy Modeling Wizard.

Click Next to bypass the wizard's welcome screen, and you will be taken to the Domain Controller Selection screen, shown in Figure A. As you can see in the figure, the screen asks you to choose the domain that you want to analyze, and then asks you to either choose a domain controller or specify that any domain controller can be used.

Figure A You must specify the domain that you want to analyze.

Click Next, and you will be taken to a screen that asks which user and/or computer you want to simulate the policy settings for. In both cases, you can either specify a particular container or an individual user and/or computer. That way, you can either evaluate a specific user and/or computer, or you can about your weight all of the users and/or computers within a particular container. You can see what this screen looks like in Figure B.

Figure B This is where you specify the Active Directory objects that you want to evaluate.

Click Next, and you will be taken to a page that gives you the chance to select a particular site. If you do not have any non-default sites defined, then you can just skip this page by clicking Next.

The next page that you will see allows you to enter alternate network location for a user and computer containers. The basic idea behind this screen is that it allows you to perform various what if scenarios. For example, you can see what would happen to the group policy settings if you were to move the computer in question to a different Active Directory container. Of course you do not have to specify an alternate location unless there is a particular location that you need to test.

When you click Next, you will see a screen listing all of the security groups that the currently selected user is a member of. You have the option of simulating changes to the users group membership if you want. When you're done entering any desired changes, click Next. You will now be given the chance to entering WMI filters that you want to use. Add any desired filters, and click Next.

You should now see a summary screen listing the options that you have specified. Make sure that everything looks okay, and then click Next, followed by Finish. When you do, Windows will display a screen similar to the one that is shown in Figure C. This screen allows you to see the outcome of your proposed configuration.

Figure C Your proposed changes are displayed in the Group Policy Management Console.

Conclusion

In this article, I have explained that it is sometimes difficult to evaluate the outcome of changes to the group policy. I then went on to show you how to use group policy modeling as a way of testing your proposed changes before you actually implement them.