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Banner grabbing for beginners

Hello, aspiring ethical hackers. In this blogpost, you will learn about banner grabbing. Banner grabbing plays a very important role in ethical hacking for penetration testers and hackers alike. To understand what is banner grabbing, you need to understand what is a banner first.

What is a Banner?

A banner is the information displayed by software or service running on a specific port. This information involves the type of software running, version of the software running etc. This information is displayed by default by every software running for marketing purposes.

What is Banner grabbing?

Banner grabbing as its name implies, is grabbing this banner. A banner when displayed to a common user may provide information to the user. In the same way, by grabbing this banner, hackers and penetration testers can get information about the software running on it and the version of the software running. This allows them to search or research for any vulnerabilities in the software.

Types of Banner grabbing

Banner grabbing can be performed in two ways: Active & passive.

  1. Active banner grabbing: In active banner grabbing, a hacker or penetration tester interacts with the software & target services to grab the banner.
  2. Passive banner grabbing: In passive banner grabbing, a hacker or penetration tester doesn’t interact with the target service while grabbing the banner. This can be done by packet sniffing on the network traffic of the network.

Although banner grabbing can be performed on almost all services running on all ports, the most common services that are used for banner grabbing are,

FTP-Port 21
SSH-Port 23
SMTP-Port 22
HTTP-Port 80

Tools used for Banner grabbing:

  1. Telnet, wget, curl etc

Apache:

Imagine I have set up a website named www.shunya.com on an Apache server. A hacker can easily find Information about the web server in different ways. For example, a hacker can visit the website and and try to open a webpage which is not existent on my server, like below.

banner grabbing

In the above example, hacker tried to open page named “admin.php” which was not available on my server and in turn the server responded with a type of web server, the target OS and the scripting language. This is giving out too much information.

The traditional and popular way of fingerprinting is through telnet. A hacker opens command line or terminal. and types the command “telnetwww.shunya.com 80″. When the screen goes black, type “HEAD / HTTP/1.0″and this will give the server information.

There are also many fingerprinting tools available. I am gonna show you only one, Id serve. Let’s see how to banner grab using Id serve.

Now what are the preventive measures we can take in Apache server to disable or atleast prevent fingerprinting to some extent. Apache web server has a configuration file called “httpd.conf” where we can make changes to fight fingerprinting. Go to httpd.conf and change the value of the option “Server Signaturetooff”.This will not display any information about server when an nonexistent page has been accessed.

In the httpd.conf file, changing the value of “Server Tokens”from “Full” to “Prod” will only show the minimum server information as shown below.

This still discloses that our web server is Apache but it doesn’t show the version. In Kautilya’s words this is delaying the march of enemy. Here are the options we set.

IIS 8:

Now imagine we changed our www.shunya.com website from Apache server to the latest version of Microsoft web server, IIS 8. To prevent error pages form revealing any information in IIS server, we can set custom error pages. Now let’s use IDserve tool to fingerprint the IIS 8 server.

It shows the server version. Now how can we prevent this. Microsoft provides a tool named UrlScan freely available for download which can be used easily to process HTTP requests. Download this tool and install it. ( See how to configure Urlscan for IIS 7.5 and IIS 8 ). Then go to the configuration file of UrlScan, “UrlScan.ini” located at “C:WindowsSystem32inetservUrlscan”by default and change the value of “RemoveServerHeader’ from “0″ to “1″.

This will not reveal the server version information as shown below.

We can further mislead the attacker by setting our server name to some other value different than our original one. This can be done by setting the value of “RemoveServerHeader” to “0 “and changing the value of “AlternateServerName” to the value we want to specify ( in our example Nginx ).

So when the attacker tries to fingerprint our website, he will be misleaded.

Note: Taking this preventive measures will not stop a determined hacker to find out our server information.

That’s all in webserver banner grabbing and countermeasures.

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Configure UrlScan on IIS7.5 and IIS8

UrlScan is a security tool used to restrict types of HTTP requests that IIS will process. It is a simple tool which is very helpful in blocking harmful requests to the server. It seemingly supports only IIS 5.1, IIS 6.0, and IIS 7.0 on Windows Vista and Windows Server 2008. It has been deprecated since IIS 7.5 and IIS 8. It is said that Microsoft has included the features of UrlScan in request filtering option for IIS 7.5 and IIS 8. But it definitely is not a match for the simplicity of UrlScan. Today I am going to show you how to configure UrlScan in IIS 7.5 and IIS8. (IIS 7.5 is available in Windows server 2008 R2 and IIS 8 is available in Windows Server 2012 and Windows 8 ).

I am going to configure this in Windows server 2012 i.e IIS 8 but do not worry the configuration steps are similar in IIS 7.5. First and foremost install Web Platform Installer in your machine. This will help us to install all the components we require in simple steps. From web platform installer, select component IIS 6 metabase compatibility. This is compulsory to install URLscan.

Then, select IIS ISAPI Filters. (ISAPI filters may already be installed in IIS 7.5 ).

Click on Install. You are shown a review of components you selected to install. Click on I accept.

The components are installed and will show you a Finish screen. Click on Finish.

We are all set to install UrlScan. Download Urlscan and click on the msi package. On the window, select the option “I select the terms of license agreement” and click on “Install”.

The installation is very quick. Once it finishes,click on “Finish”.

Now open IIS Manager. Click on ISAPI filters.

If everything went well, we should see a filter already set like below.

Click on it. We can see that there is already a filter named URLscan 3.1 linking to the executable urlscan.dll.

urlscan

Before configuring UrlScan, let’s try a little banner grabbing to check whether UrlaScan is working or not. For this, we will use tool Idserve to fingerprint the server on which we have configured UrlScan. (www.shunya.com is fictional website i set on my server ).

We can see that the version is Microsoft-IIS/8.0. Now let’s go to the configuration file of urlscan (urlscan.ini) to make some changes to it. It is located by default at “C:WindowsSystem32inetservurlscan”and change the value of “RemoveServerHeader” to “1” from “0”. Save the file.

Now let’s again try to banner grab using Idserve. Restart the web server.

urlscan

We can see that the server version has not been disclosed hence our UrlScan is working successfully. Hope it was helpful.

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Virtual hacking lab for beginners

Hello, aspiring ethical hackers. In this blogpost, you will learn how to create a virtual hacking lab for practicing hacking. No matter how many articles or blogposts you read or how many hacking courses you take, you cannot truly understand the concept of hacking until you perform those hacking tutorials practically. To practice hacking effectively, you need a secure environment without the risk of compromising the security of a safe network or systems and attract legal consequences due to your actions.

What is a Hacking lab?

A hacking lab is a lab that provides a safe environment to practice hacking without the above-mentioned risks. The most basic hacking lab consists of two machines: attacker system (the system from which you hack) and target system (the system which you hack).

What is a virtual hacking lab?

Just now, you have learnt that a basic hacking lab needs to have one attacker system and target system. They can be installed on separate hardware but this may prove expensive especially as you upgrade your hacking lab in future. Luckily, hacking labs can be created on a single system itself using virtualization solutions. Virtualization allows you to install multiple operating systems on a single machine. Some of the popular virtualization solution are Oracle VirtualBox, Parallels Desktop, VMware vSphere, Hyper-V, QEMU etc.

The hacking labs created using this method is called virtual hacking lab. They are inexpensive compared to the cybersecurity lab and easily adaptable. Of all the solution mentioned above, I will be using Oracle Virtual Box as it is FREE and also rich in features. Oracle VirtualBox can be downloaded and installed on Windows, Linux, macOS, Solaris etc. Here, I have installed virtual Box on a Windows machine.

How to create a virtual hacking lab?

Let’s create a simple hacking lab with an attacker system and target system on VirtualBox. The operating system on which Oracle VirtualBox (or any another virtualization software) is installed is known as the Host machine. The operating systems that are installed in Oracle VirtualBox as called as GUEST machines. So here, in VirtualBox, we are going to install two guest machines: one is Kali Linux (attacker system) and Metasploitable 2 (target system).

What do we need?

1. Oracle VirtualBox. (Download)

2. Kali Linux. (Download)

3. Metasploitable 2. (Download)

Install Kali Linux and Metasploitable 2 in VirtualBox.

See how to install Kali Linux in VirtualBox.

See how to install Metasploitable 2 in VirtualBox.

Once both the virtual machines are installed, turn on both the machines. Login into the Metasploitable 2 VM. Default username and password are “msfadmin / msfadmin”.

Type the command “ifconfig”to find out the IP address of your target system.

Similarly login into the Kali Linux machine and in the terminal, type command “ip a” to find out its IP address.

Test whether the attacker system can communicate with the target system by pinging the target system from the attacker system as shown below.

The connection is successful. Our virtual hacking lab is ready. Happy practicing hacking.

Various networking modes of VirtualBox

Above, we created a simple virtual hacking lab successfully. Go to “settings” of any of the above GUEST machines and go to “Network settings”, you will see that this Guest machine is attached to a NAT adapter.

When you install a GUEST machine in VirtualBox, the default network mode is NAT. Apart from NAT, there are other network modes on VirtualBox.

Each networking mode plays a different role in hacking. So, it’s good to learn about each of them.

1. NAT:

NAT stands for Network Address Translation (NAT). This is the default networking mode of VirtualBox. This mode allows web access, downloading of files from internet, etc. Our simple lab above is NAT. This is used to create a hacking lab when both attacker system and target system need internet access.

2. NAT network:

This is useful in creating hacking lab on a separate internal network that uses outbound connections.

3. Bridged adapter:

When you use a Bridged adapter, the virtual machine uses the network adapter of the Host machine and acts as a separate machine in the LAN network of the Host machine.

4. Internal network:

This creates a different kind of network separated from the host system. This network doesn’t have access to the outside internet.

5. Host-only network:

This creates a network in which the virtual machines have access to the Host machine.

6. Not attached:

In this type of network, the virtual machine is disconnected from everything. This might be useful in creating a malware analysis lab.

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How to install Metasploitable 2 in VirtualBox

Hello aspiring Ethical Hackers. In this article, you will learn how to install Metasploitable 2 in VirtualBox. What is Metasploitable? Learning penetration testing or ethical hacking requires practical knowledge and good practice needs a vulnerable target. That is where Metasploitable comes into picture. It is an intentionally vulnerable operating system made by the makers of Metasploit themselves so that aspiring ethical hackers can practice and hone their hacking skills. As its name conveys Metasploitable is loaded with vulnerabilities that can be exploited with Metasploit modules.

This virtual machine can be used to conduct security training, test security tools, and practice common penetration testing techniques. For this i am going to use Metasploitable 2 which can be downloaded from here. After downloading the zip archive, extract the files into a folder. The file contents look like below.

Installing Metasploitable

Open VirtualBox and click on “New Virtual machine wizard”. Type the name of your choice. I am using ‘Metasploitable-2‘. Choose ‘Type’ as Linux and ‘version’ as Ubuntu. Click on “Next”.

Choose the memory size appropriate to the availability of RAM on your host machine although 512MB is more than enough. Click on “Next”.

In the hard drive creation window, select option “Use an existing virtual hard drive”, browse to the folder where we have extracted our zip files and select the ‘vmdk’ file available. Click on “Create”.

Then you are automatically booted into the metasploitable OS. The default username and password are “msfadmin”.

You learnt how to install Metasploitable 2 in VirtualBox. See how to create a penetration testing lab.

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How to install Kali Linux in VirtualBox (2024)

Hello, aspiring ethical hackers. In this blogpost, you will learn how to install Kali Linux in VirtualBox. The makers of Kali Linux have a released the latest version of the popular pen testing distro. So, we decided to update this article on how to install Kali in VirtualBox.

Every latest version of Kali Linux has many brand new features. Now, let’s see the simplest process to install Kali Linux in VirtualBox. The makers of Kali Linux provide pre-built VMs for popular virtualization software like VMware, VirtualBox, QEMU and Hyper-V. Go here and download the pre-built image of VirtualBox. We have performed this installation in the Oracle VirtualBox 6. In this article, we will be installing Kali Linux 2024.2 but the process is same for any version of Kali Linux.

The pre-built image will be downloaded in the form of an zip archive. Extract the contents of the zip archive. Your downloaded contents should look like below. As you can see, there will be two files: Virtual Disk Image (VDI) file and VBOX files.

Now open VirtualBox and go to Machine > Add. You can also use shortcut “CTRL+A” to get there.

In the window that opens, browse to the directory that consists of contents of the zip archive we have extracted at the beginning of this article. A window like below will open. Browse to the OVA file we downloaded.

Only the vbox file will be displayed. Select this file. Doing this will successfully create the virtual machine on VirtualBox as shown below.

Power ON the virtual machine by double clicking on it. You should see the login screen as shown below.

Happy hacking practice.