Tuesday, December 23, 2014

ShmooCon Ticket Contest Writeup

We have a winner @bacnstrips! With a very close second place to @Nheafer! Congrats!
@bacnstrips was nice enough to do a write up on exactly how he solved the challenge:

This challenge covers a few different areas, including binary analysis, password cracking, stenography, and encryption. None of steps required in-depth knowledge of any particular area.

For this challenge I used Kali Linux. I found that almost the entire challenge could be solved with the programs contained in Kali Linux. The only required program Kali did not include was Open Stego. .

Once set up, I downloaded the evil.exe and looked at it's properties. Evil.exe is a Windows executable. What do we do with this file? I am pretty sure running a file called “evil.exe” is not something we are inclined to do. I started by using the Linux strings tool to look for clues and useful bits of information.

To make the results a little more manageable I set the -n flag to control the size of null terminated strings that are returned:

strings –n10 evil.exe

In the results I noticed:


Strings just revealed a user name, domain name, IPv4 address and a clue. A hex dump of the file might give us more information. This can be done either with:

hexeditor evil.exe


xxd evil.exe > evil_hexdump

Searching for the string “BETWEEN THE NULL BYTES” to quickly find a useful section of the dump.


Looking at this portion the string “hash:” can be seen, and since the clue is “IT IS BETWEEN THE NULL BYTES!!” try looking for the null bytes (x00) in the hex.

Administrator, EXPLOITS.LOCAL can be seen a few lines above “hash:” and 5F 69 62 58 DC E9 FF 60 6B F3 FB 3D 1A 3B 86 F9 (which follows “hash:”) are all nicely wrapped null bytes.

The hash is probably a password, so that should be cracked but what type of hash is it?. Hash-identifier might shed light on possible hashing algorithms and hash-identifier returned:


Because there is a user name and domain name, Domain Cached Credentials seemed like a good place to start This hash can be cracked using hashcat:


Or you could use John the Ripper:


Both tools quickly revealed that the password was “welcome1”. Now I needed to find out what I could do with the password.

Opening up a web browser and going to shows a seemingly default web page. However the page does say that “somethings have been changed”.


Although it is hard to see in the screenshot, viewing the source revealed a commented out image tag for “shmoo_opensteg.png”. Manually browsing the image shows:


The filename says that stego is involved, which means we will have to extract something from the picture. Scalpel can extract hidden files, but in this case it did not recover anything useful.

Most stego tools usually have their own particular method of hiding data, searching Google for “OpenSteg” shows that there is an open source tool called “Open Stego”.

After downloading and installing Open Stego and providing the password “welcome1” a hidden file called “README” is extracted.

The README file was for pyFTPd a python FTP server, except with a couple lines added to the top. These couple of lines indicated that pyFTPd had been installed with default accounts enabled.

It didn’t say where the FTP server was but running nmap against with a banner grabbing does.

nmap -sS -sV -v -n -Pn --script banner
Here are the results:
Starting Nmap 6.47 ( http://nmap.org ) at 2014-12-12 18:55 EST
NSE: Loaded 30 scripts for scanning.
NSE: Script Pre-scanning.
Initiating SYN Stealth Scan at 18:55
Scanning [1000 ports]
Discovered open port 80/tcp on
Discovered open port 22/tcp on
Discovered open port 2121/tcp on
Completed SYN Stealth Scan at 18:56, 7.45s elapsed (1000 total ports)
Initiating Service scan at 18:56
Scanning 3 services on
Completed Service scan at 18:56, 6.22s elapsed (3 services on 1 host)
NSE: Script scanning
Initiating NSE at 18:56
Completed NSE at 18:56, 5.48s elapsed
Nmap scan report for
Host is up (0.099s latency).
Not shown: 993 closed ports
22/tcp open ssh OpenSSH 6.0p1 Debian 4+deb7u2 (protocol 2.0)
|_banner: SSH-2.0-OpenSSH_6.0p1 Debian-4+deb7u2
25/tcp filtered smtp
80/tcp open http Apache httpd 2.2.22 ((Debian))
135/tcp filtered msrpc
139/tcp filtered netbios-ssn
445/tcp filtered microsoft-ds
2121/tcp open ftp pyftpd
|_banner: 220 Welcome to pyftpd. Happy downloading.
Service Info: Host: Welcome; OS: Linux; CPE: cpe:/o:linux:linux_kernel

NSE: Script Post-scanning.
Read data files from: /usr/bin/../share/nmap
Service detection performed. Please report any incorrect results at http://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 19.29 seconds
Raw packets sent: 1048 (46.112KB) | Rcvd: 1045 (42.316KB)

There it is, running on port 2121, pyftpd! Just needed the default account credentials to log into it.

Searching Google for pyFTPd, returns references to CVE-2010-2073 (http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-2073) where pyFTPd had an issue with default credentials. Additionally Google helps find the pyFTPd source code.

Some of the disclosures contained the following excerpt from auth_db_config.py:

passwd = [('test', 'test', 'CY9rzUYh03PK3k6DJie09g=='),
('user', 'users', '7hHLsZBS5AsHqsDKBgwj7g=='),
('roxon', 'users', 'ItZ2pB7rPmzFV6hrtdnZ7A==')]

However there are no references to the plaintext version of these passwords. Time to crack some more hashes… A quick peek at the source code for pyFTPd to determine what hashing algorythm was being used revealed that MD5 was used.

After crafting another hash file and running it through hashcat or John the Ripper we get the following user names and passwords back:

test : test
user : user
roxon : noxor

Since test and user seem pretty uninteresting I started with the roxon account.


It Worked! The only file available was "Acrobatics Earthliest Subinfeudatorys Enchanted Creative Broad.data". Downloading it and opening it in a hexeditor gives us no useful information.
The file is not readable, it is probably encrypted. Looking closely at filename, the first letter of each word spells out “AESECB”. That is our next hint. While we don't know whether it is 128, 192 or 256 bit, there aren't that many to try.

First I tried using openssl to decrypt the file using:

openssl aes-128-ecb –d –in <encrypted file>

When prompted for the password “welcome1”, results in an error… “Bad Magic Number” I tried a few other strengths of AES ECB but still no luck!


Searching Google for AES ECB Decryption tools, will lead to a few sites that will decrypt files . NEVER use a website to decrypt sensitive files! One off the sites (http://aes.online-domain-tools.com/) would accept the key in either plaintext or hex, but it automatically converted plain-text to hex in order to decrypt. This can be done using the –K flag and the hex equivalent of “welcome1”.
Attempting to decrypt results in the plain-text message when openssl throws an error, to eliminate the error, add the -nopad flag. With all of the flags, openssl gives the plain-text without any errors:


This returned:

Congrats you have reached the end! Send a PGP encrypted email answers@projectmentor.net with this public key 33A45714258D9AC8

That's the final flag! The only thing left to do was send the PGP encrypted email.


Thanks a ton to @bacnstrips again for the great walk through. One other option to solving the AES encryption without needing to know the bits was with a short bit of python:

#!/usr/bin/env python

import binascii
from Crypto.Cipher import AES

skey = 'welcome1'
key = bytes(skey)
blocksize = 16
padding_required = blocksize - (len(key) % blocksize)
padChar = b'\x00'
data = key.encode('utf-8') + padding_required * padChar
cipherhex = "9c733b26742bd75854f7e60384d0cae120f115e14fa2f2a197068bb8f77588315c6ef33f3617a49732c15117321b14e7f80dac6850cc67e84ac827b23ccc9ffea9da5c8133c85fff1a83d8fa0e64676c1535bfba29550d6fa232aa829413450a9f53c900102ace043a9721e5c8c77339d32c44002cd8dd7025ef387146aa4a7f"
ciphertext = binascii.unhexlify(cipherhex)
decobj = AES.new(data, AES.MODE_ECB)
plaintext = decobj.decrypt(ciphertext)

print plaintext

Which results in the exact same result as with OpenSSL

Thursday, December 11, 2014

ShmooCon Ticket Contest Extension and Hint


The challenge has yet to be achieved completely by anyone yet, and I have only received questions from 2 individuals so far, so the contest will extend until someone either gets to the end, or it's the day ShmooCon starts and I simply auction it off for Hackers for Charity funds.


As a possible way to spur things along, I will say that the exe contains two things that you _must_ have to continue on, an IP address and some sort of password in hashed form, and the password should be very simple to break so if you are wasting hours on it, try another format.

Monday, December 8, 2014

2014-12-08 The Shmoo Ticket Contest


And... GO!


Remember, most complete answer wins the free ShmooCon ticket. Good luck!

Also, in the spirit of Project Mentor, this is an OPEN contest in the sense that you should feel free to send in questions and expect non-misleading responses (not necessarily answers, but won't just say "Try Harder" either)

Saturday, December 6, 2014

FREE ShmooCon 2015 Ticket

Thank you all so much for participating with Project Mentor over the time (intermittent that it's been) we've been running it.

If you don't know what ShmooCon, it's an amazing Infosec / Hacking conference held in Washington DC every year (usually Jan/Feb). You can find out more here: https://www.shmoocon.org/

They have a wonderful program called "Shmooze a Student" where a potential attendee pays $400 for the usually $150 ticket. This program takes the extra money and puts it towards getting a student that normally couldn't afford to go, the opportunity, and side cast to make it out to the con. You can find out more about the program here: https://www.shmoocon.org/shmooze_a_student

That brings us the the purpose of this blog post. Tomorrow is the last day to get a ticket to ShmooCon the regular F5 assaulting way. On Monday (December 8th 2014) I will post another Project Mentor challenge. This challenge will involve a few different Infosec topics. The person who submits the _most complete_ answer by Friday, December 12th 2014, will win the ticket and also be invited to present their walk through during the lunch time block at ShmooCon Epilogue.

If you are unaware of how Project Mentor works you can find out more here: http://www.projectmentor.net/p/what-is-this.html

Thursday, December 4, 2014

2014-12-04 Beginner Reverse Engineering

Reverse Engineering is done for a number of reasons and on a number of different types of programs and products. Below is a link to an executable called "passwords_suck.exe". Your job is to tell me what the right password is, and anything else you can find inside that binary. There are many tools to do this so don't just get fed up with the complexity of IDA or other professional grade tools.

Good luck!


Monday, August 18, 2014

2014-08-02 Challenge: Web enumeration - Target


One of the readers suggested that I set up a place where readers can test out and try their hands at enumerating on a "authorized" site. Well, I have stood up a web server, and there are roughly 22 pages that are enumerable using one method or another.

 Good luck!

UPDATE: Each discovered page contains a hash, it's simply a way to verify you have found something that was intended to be found. You can submit them as well or just shoot over the URL of the pages you found.

Please send in your answers or ask questions, this isn't a secret or CTF, this is here for you to learn.

Saturday, August 2, 2014

2014-08-02 Challenge: Web enumeration

Many times during application assessments the discovery of pages or objects that were meant to have been removed or "disabled" are the ways in. Hidden functionality or "admin only" functions that don't require auth to name a couple others. The question usually comes down to finding them. So, name 6 ways / methods of discovering content on web applications.

Sunday, July 6, 2014

2014-07-04 Challenge: RFID

With RFID you have low and high frequency "tags" or cards and they aren't all the same. List 2 types for each frequency level and what they are generally used for. Then see if you can find out what types of attacks are viable against the 4 you picked and what specific hardware you might need to attempt those attacks. Provide scenarios.

Thursday, June 12, 2014

2014-06-14 Challenge: Hash Identification

Turning out to be a monthly gig rather than a weekly one. Either way, here is this week's challenge, identify and crack the following hash:


You should be able to crack it relatively quickly with a bit o' magic.

(UPDATE: Had to change the hash since everyone and the mother got the original one right off the bat)

Wednesday, May 7, 2014

2014-05-05 Challenge: Bad Characters

During exploit development there is the concept of "bad characters". What are they? What are some common "bad characters" when trying to exploit 1) HTTP 2) FTP 3) Programs written in C

Monday, April 14, 2014

2014-04-14 - Back in the saddle

I apologize for the absence but I've honestly been crazy busy with CCDC (MACCDC prep and execution, and NCCDC prep). It would have been unfair of me to issue challenges without being able to properly respond to them in a timely manner. I do have a few left to answer still. So this week's challenge is going to require a big more research than normal. The following is a Windows 7 event log of some sort. With it you should be able to tell me the computer name, and exactly what time KB982132 was installed.
(The file is intentionally corrupted)

Download: https://drive.google.com/file/d/0ByiDshWJ_PnZbTR3QTNyYUJVUGM

Monday, March 10, 2014

2014-03-10 challenge

This week's challenge is straight forward. "sc" is a Windows command that shows information about Windows services. Pick any service on a windows machine and run "sc sdshow " on it (you can use "sc sdshow lanmanserver" if you want. The output of the command is called a "DACL" in "SDDL". Your challenge is to explain in its entirety what that jumble of letters and semicolons mean, as well as explaining DACLS and SDDLs. Extra Credit: Explain how an attack can use this information.

Monday, March 3, 2014


Is it Monday already? Sorry for being tardy on the emails this weekend I will get to all of them tonight. I was a little busy making RIT students do push ups in order for me to relinquish control of their domain controllers for ISTS ;-)

See the fun we had here: http://www.reddit.com/r/ISTSRedTeam/

This week's question is:

Describe XML Entity Injection, how it can be found (what indicators may lead you to assuming it's possible on a given app) and what is possible with it?

Monday, February 24, 2014


First a few FAQs:

  1. I prefer that people email in their answers but a link to a blog post works as well. But I probably wont see them if you post it on social media sites like Facebook or G+. 
  2. I won't be posting anything about the answers submitted, to include what the "right" answer is, this isn't trivia, this project is geared towards challenging you to try something out you may not have tried, or learn something you might not have tried to learn, I'm only here to push you further once you have and keep it rolling week by week once you do.
This weeks question is:

A number of SCADA and ICS systems use a protocol named "MODBUS" what are some vulnerabilities that are in or involved this protocol? What sort of systems were they attached to? What did they control? Why did the vulnerabilities occur? What does SCADA stand for? What does ICS stand for? Dive as deep as you want on this.

Wednesday, February 19, 2014

Groupon Certifications

Since this blog is about challenges and helping people learn/break into the IT Security field (InfoSec) thought this was something worth posting:

$99 for a certification bundle (CompTIA Security+, A+, and Network+), as far as I can tell, this is only training to help prep for the certifications. I don't know anything about the company, but the demo video seems pretty lively.

Link: http://www.groupon.com/deals/it-university-online-45-washington-dc

Thursday, February 13, 2014


(Because this is the first post, and you probably don't know what "this" is, check out the page: http://www.projectmentor.net/p/what-is-this.html to find out)

Tomorrow is Valentines and the 17th is a Holiday, so this question comes a little early:

802.11 is commonly know as WiFi. Name 2 different attacks you can perform on the different types of Wifi, feel free to classify what I mean by "types" however you wish. Please provide reference or your own work at trying them out.

Due Date: 2014-02-21