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Posted on August 18, 2016November 18, 2024 by kanishka10 — 6 Comments

Beginners guide to Backdoor

Hello, aspiring ethical hackers. In our previous blogpost on maintaining access, you learnt the importance of maintaining persistence on target networks in hacking or a pen test. In this blogpost, you will learn about backdoor, one of the techniques used to maintain access on a target network.

What is a backdoor?

A backdoor is any method or technique other than the conventional method that that gives us continuous access to our target system, software or network.

According to Wikipedia, “A backdoor is typically a covert method of bypassing normal authentication or encryption in a computer, product, embedded device (e.g. a home router), or its embodiment (e.g. part of a cryptosystem, algorithm, chipset, or even a “homunculus computer”—a tiny computer-within-a-computer such as that found in Intel’s AMT technology).

Next question is why we need to create a backdoor? Once we gain access to a network (or after privilege escalation), there are chances that our intrusion is detected and security measure applied. Once this happens, our access to the target is lost. That’s why we need to create a backdoor.

Now, since you have understood what is a backdoor and its importance, let’s see an example of a backdoor. What better example than using Metasploit framework to demonstrate this. Metasploit has an inbuilt feature for creating a backdoor within meterpreter called persistence module. This method comes to use after gaining a meterpreter session on a Windows system. After gaining a meterpreter session on the target system, run the command given below.

run persistence -h

It will show you all the options we can set for our backdoor. All the options are self explanatory in the image given below.

Now I want my backdoor to start as soon as the system starts. So I chose ‘X’ option. After starting, I want it to make connection attempt to my attacker system every three seconds, so I kept the interval(i) as 3. The port on which connection should be made is 443. The option (r) is remote system’s IP address i.e the IP of the system to which the connection should be made.

Remember this script will be installed on the target system. Run the script. As you can see, the file is installed in the autorun.

Image explaining how to Backdoor Windows with Metasploit

Now it’s time to start a listener on our attacker system. It can be done as shown below.

Change the options accordingly as we set in the persistence script and start the handler. If the system is live, we will get the meterpreter shell as shown below.

Posted on August 15, 2016November 13, 2024 by kanishka10 — 6 Comments

Beginners guide to hash cracking

Hello aspiring ethical hackers. In our previous blogpost on cryptography, apart from learning the uses of encryption in cybersecurity, you learnt about various encryption techniques. One such method is hashing. In this article, you will learn about hash cracking.

The process of cracking a password hash is known as hash cracking. In ethical hacking, you will definitely encounter password hashes. You will have to learn how to crack these hashes to be able to move forward in pen testing or Red teaming. For example, let’s say you encounter NewsP Free News Script 1.4.7 software in the target network. This particular version of software had a credential disclosure vulnerability as shown below. The only thing that stops me from accessing the website is the password in encrypted format.

Image explaining how to crack hash es with kali linux

The first step in cracking hashes is to identify the type of hash we are trying to crack. We can identify a hash type using a tool named hash-identifier. This tool is installed by default on Kali. Open a terminal and type command given below.

hash-identifier

Enter the hash we need to identify as shown above and hit ENTER. It will show the possible hash type as shown below. In our case, it is MD5 hash or a variant of it.

We can also use another tool “hashid” for hash identification. It’s syntax is as shown below.

hashid <hash>

Since now we know that the hash type is Md5, it’s time to crack the hash. We will use a tool called ‘findmyhash’. This tool tries to crack the hash by using various online hash crackers available. To use this tool, we need to specify the hash type ( which we already know ) and hash after it as shown below.

findmyhash <hash type> -h <hash>

After successfully cracking the hash, it will display us the password as shown below. In our case, the password is admin.

Posted on August 13, 2016November 8, 2024 by kanishka10 — 3 Comments

Beginners guide to Arcanus Framework

Hello aspiring ethical hackers. In our previous blogpost, you learnt what is a payload and about what is a payload generator. In this blogpost, you will learn about one of the payload generators, Arcanus Framework. Arcanus is a customized payload generator that can generate payloads which are undetectable by almost all of the antiviruses (till date ). This could be very useful in penetration testing.

Let’s see how to use Arcanus Framework. To install this tool on Kali Linux, we need to install golang. Install Golang and then clone the Arcanus repository from Github as shown below.

Navigate to the ARCANUS directory created and view its contents. We should see a file ARCANUS_x86. Let’s first generate a Windows payload. We will generate a x_86 payload. First change its permissions as shown below.

Next run this file. You should see an ARCANUS logo as shown below.

You will see five options as shown below. Since we are generating a Windows payload, we will choose option 2.

Image explaining Windows hacking with Arcanus framework

It will prompt you to set the attacker system’s IP address ( in our case the address of Kali Linux ) and a port on which you want to start a listener for the reverse shell. Enter the values and hit “Enter”.

It will generate the payload and automatically start a listener as shown below.

The payload will be generated with the name “payload.exe” as shown below in the ARCANUS directory.

Next we need to send this payload to the victim using Social engineering. When the target user clicks on the payload we sent, we will get a shell on the target system as shown below.

That’ s all in Windows hacking with Arcanus. Now let’s see how to generate a payload for Linux target. Select the option 3 since we are generating a Linux payload.

The rest of the steps are same as generating a Windows payload. Enter your IP address (Kali Linux in this case) and the listening port as shown below.

It will generate the payload in the same directory start to automatically listen for a reverse shell as shown below.

Send the generated payload to our victim. When he executes it, we should get a shell on his system as shown below.

Posted on August 9, 2016March 21, 2024 by kanishka10 — 3 Comments

Webshell attack with msfvenom

Hello aspiring hackers. In our previous howtos, we saw about different shells like the infamous c99 shell, web shells in Kali Linux and Weevely. In this howto, we will see how to perform webshell attack with Metasploit. We will be getting a meterpreter shell on the website.

One of the wonderful features of Metasploit is creating payloads as per requirement. Using msfvenom, we can create binaries for Windows, MAC and Linux. We can also create shell payloads for websites in different formats like php, asp , javascript and asp. In future howto’s we will definitely learn more about msfvenom but for this howto, we will create a php payload.

As you can see below, I have created a php payload named “shell.php” with the metasploit payload option “php/meterpreter_reverse_tcp”. This gives us a reverse php meterpreter shell. The “lhost” option is our attacker system’s IP address and “lport” the port on which we want php meterpreter shell back.

Image explaining webshell attack with metasploit

After the shell is successfully created, let’s start a listener with Metasploit as shown below. Remember to set the same payload we set while creating the payload.

Set the lhost and lport as shown below. They should match with the values in the shell we created. Type command “run” to start the listener.

Now you need to find a site vulnerable to file upload. For this howto, I’m using my own vulnerable webapp “Vulnerawa”. To know more about Vulnerawa go here. Vulnerawa has a file upload vulnerability in its careers page.

Go to its file upload page and upload the shell. That shouldn’t be a big problem.

Now go to the shell we just uploaded through the website. Normally its located in the uploads directory ( In real websites, you need to locate it ). The shell will look like below.

In the listener we started an the attacker system, we should have already got the meterpreter shell. Happy hacking.

That is how we perform webshell attack with Metasploit.

Posted on August 4, 2016October 23, 2024 by kanishka10

WAPT with HPWebinspect : Part 2

Good evening friends. Today we will see the second part of WAPT with HPWebinspect. If you didn’t go through the first part, we ended it by scanning a website for vulnerabilities. The results have given us vulnerabilities categorized as critical, high, medium and low. That was the easiest part. Now we will go through analysis of these vulnerabilities.

Wait, but why do we need this analysis? Just because we have used an automated tool doesn’t mean it is cent percent effective. There may be lot of false positives and in the worst case false negatives. The threat it shows as critical may not be really that dangerous or a threat it shows as medium may be critical depending on the situation.

The analysis part is very important part of the WAPT. Let us see how to perform this analysis . We will take our previous scan report.

Before we do the analysis, let us have a look at the interface of HPWebinspect. To the down left, we have view options of the scan ( site and sequence ). The “site view” shows us the hierarchical structure of website we just scanned with vulnerabilities found highlighted as shown below to the left. We can see that in account part of the website there is a critical vulnerability.

The sequence view shows us the order in which WebInspect scanned the URLs. It is shown below.

Occupying large area of the interface is the Scan dashboard with a pictorial representation of vulnerabilities. It also has vulnerabilities classified into its attack types ( how exactly these vulnerabilities will be used ).To its left, we have sections called scan info, session info and host info. The scan info has four options : dashboard, traffic monitor, attachments and false positives. We have already seen dashboard and others are self explanatory.

Below scan info we have have session info. It is empty because we didn’t include any sessions in our scan.

Below session info, we have the host info which is obviously information about the host we scanned. It will provide us info like P3P info ( protocol allowing websites to declare their intended use of information they collect about users) , AJAX, certificates etc, etc, etc. Let us look at the cookies collected by the scan.

It also shows us the emails we found during scan.

Also the forms.

Now we come to the most important part of the interface which is right down below. These are the vulnerabilities found during the scan. As already said, these are classified according to the dangers posed by them but there may be false positives. We need to analyze each vulnerability for this exact reason.

In this howto, we will cover analysis of one or two vulnerabilities. Expand the “critical” section of vulnerabilities. We can see that there is a XSS vulnerability in the search page. We will analyze this vulnerability.

Click on the vulnerability. The dashboard of HPWebinspect will show information about the particular vulnerability ( in our case XSS ) and how hackers might exploit this.

Scroll down the dashboard to get more info about the vulnerability. We can see the exact query used by the tool to get the result. In this case, our target is using tag removal to prevent XSS but we can bypass using the query given below. ( We will learn more about XSS and its evasion filters in a separate howto)

Now right click on the vulnerability we are analyzing. In the menu that opens, click on “View in Browser” to see this exploit practically in the browser.

We can see the browser result below. In this case, it is displaying a messagebox with a number but hackers can use it to display cookies and session ids. Hence this is definitely a critical vulnerability.

Right click on the vulnerability and select the option “Review vulnerability”. This is helpful in knowing more precisely about the vulnerability.

Another window will open as shown below. It will automatically show you the browser view.

We can click on “Request tab”to see the request sent by our tool.

Similarly the response tab shows us the response given by the target.

We already saw this before in the dashboard. The “vulnerability tab” give us information about the vulnerability and how hackers might exploit it. There are also options like “Retest” and “Mark as”. The Retest option allows us to test the vulnerability again. We shall see the “mark as” option below.

Close the window. Once again right click on the vulnerability. You can see the option “change severity”.

For instance, the vulnerability detected is not that critical, we can change its severity suitably to high or medium or low.

Now what if the vulnerability detected is not an actual vulnerability. This is known as false positive. For example, we have this send feedback page of the target website. Let us assume it is just a false positive. In that scenario, just below the “review vulnerability” option we have “Mark as” option.

We can also access this option from the “review vulnerability” window as already shown above.

When we click on that option, we get two sub-options to mark it either as false positive as shown below

or to completely ignore the vulnerability. We can only ignore the vulnerability if it doesn’t pose any valid threat. We can also provide some description about why we are marking it as false positive or ignoring.

When we have successfully finished reviewing each vulnerability, it’s time to write the penetration testing report. To automatically generate a report, click on “Reports” tab. Select the scan for which you want to generate the report and click on “Next”.

Select whatever you want to include in your report as shown below and click on Finish.

The report generation takes some time depending on the options you selected. The report generated would be in the format as shown below. That’s all for now and in our next howto, we will see more about the tool.

That’s how we do WAPT with HPwebinspect. Want to learn Ethical Hacking with Real World Scenarios.? Subscribe to our digital magazine.

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