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Posts tagged ‘article’


Linux Bash Ncat Honeyport Script with IPTables and Dome9 Support

After securing systems by hiding them completely from the network/internet using Single Packet Authorization, I’ve recently been interested in doing more so-called ‘active’ defense, by implementing solutions to delay, confuse, or thwart attackers. Completely hiding one’s system is not always feasible (ie. in the case of an internet-facing server), and monitoring, apart from being purely reactive, is not always easy and requires the involvement of a human. An alternative to these is to do some automated active defense. One simple tool in the bag of active defense tricks is the honeyport. Read moreRead more


My Definitive List of Must-have Free Mac Applications and Best Paid-for Counterparts

These are the apps that I will install first on pretty much any new Mac that I get. I’m a huge fan of free and open source software, and no other platform has free software of the same quality and calibre as Mac OS X. Most of these are Mac-only apps (a couple are cross-platform). I’m listing free applications wherever possible, but if there is a paid-for app that I consider best-of-breed, I mention those too. Hopefully this list will help all of the techie switchers get the apps they need quickly. This list is a work-in-progress, so I’ll be adding to this it over time.

If you’re only interested in my recommended security apps, they’re at the bottom! Feel free to post in the comments if you have any you think are worth mentioning.

Last updated: 14/04/2015

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A Quick Introduction to Lockpicking and Useful Resources for Beginners

I’ve been into lockpicking for a few years now, and I’m surprised I’ve never posted more about it (maybe I will). Suffice it to say that lockpicking is great fun, you learn a lot, and one day it may come in handy (legally of course). One thing I’ve noticed whenever I talk about lockpicking, is that most people -including techies – have very little clue about how locks themselves actually work. It’s no surprise then that lockpicking feels like a bit of mystery to many. In reality the majority of locks are very simple devices, and many can be picked or bypassed using fairly simple tools.

I had the pleasure of taking part in the Defcon 19 Gringo Warrior contest where participants must bypass a series of locks to ‘escape’. It’s scored based on time and difficult of locks picked. I scored about above average. In this post I’m going to give my own shotgun intro to lockpicking, and provide some videos and links to other useful references where you can go find more detail.

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Reverse SSH over Tor on the Pwnie Express

The Pwnie Express (PwnPlug) is a great little tool for hackers, pentesters and social engineers alike. While I don’t advocate the use of a Pwnie for illicit purposes, I was intrigued about using it as an untraceable tap into a network. Out of the box the Pwnie allows you to configure reverse SSH connections, exfiltrated over a number of different protocols including HTTP, SSL, ICMP and DNS.

While these are great for getting out of controlled networks, they all require the Pwnie to be configured with the IP address of your SSH server, which could potentially be traced back to you. It also requires your SSH server to be able to directly receive connections at the IP/hostname configured on the Pwnie. While one could run an SSH server on a proxy box somewhere, I felt that was too primitive, so I installed Tor on my Pwnie and configured a Tor Hidden Service on my SSH server.

Note: For the purposes of this tutorial, the SSH server will be running on BackTrack 5. I’m assuming you’ve already performed the initial Pwnie Express setup steps on the server! Check out my PwnieScripts to help speed up and automate the Pwnie setup.

These instructions do not yet work on Pwn Plug software >= 1.1 as they’ve changed the layout of things! Will update this post when I get the time.

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PwnieScripts for Pwnie Express

The Pwnie Express (PwnPlug) is a purpose-built penetration testing device in a plug form factor. A key feature is its ability to exfiltrate from a network and connect back to your SSH server using HTTP, SSL, ICMP or DNS tunnels. Check out my tutorial on how to hack your Pwnie to make untraceable reverse SSH connections over Tor.

There are a number of steps required to set up the computer on which the Pwnie’s reverse SSH connections will be received (setting up the listeners). To simplify and automate this process, I’ve put them together into a set of very simple bash scripts. I’m hoping to turn two of these into a proper init.d script, but haven’t yet had the time. The PwnieScripts set contains the following five bash scripts, and are designed to be used on BackTrack 5 (although they can easily be adapted to work on any other distro):

  • Automates the Pwnie Express setup process by enabling SSHD, generating SSH keys, creating a ‘pwnplug’ user, installing HTTPTunnel, generating an SSL certificate, configuring stunnel, and configuring DNS2TCP.
  • Kills any existing listeners, and then starts SSHD as well as new HTTPTunnel, stunnel (SSL tunnel), DNS2TCP (DNS tunnel) and ptunnel (ICMP tunnel) listeners.
  • One-line script to monitor netstat for incoming connections from Pwnie Express.
  • aka. the Lazy Script – initiates an SSH connection to the first available established connection from Pwnie Express, so you don’t have to check which ones are active. It’ll use the more secure/relible ones first (SSL, HTTP) where available. Use the -t flag to only connect over Tor.
  • Kills all existing HTTPTunnel, stunnel, DNS2TCP and ptunnel listener processses.

Download PwnieScripts (tgz 4kb)

Any feedback or tweaks are welcome. Leave a comment below, send me an email, or message me on Twitter.


v0.1: Initial release.


Mac OS X “Lion” and the Dangers of Restoring from a Partition

With the release of Mac OS X 10.7 “Lion”, Apple is changing the way we’ll be doing system upgrades. Lion will only be available to Snow Leopard users electronically through the Mac App Store, and thus it will no longer be possible to purchase a physical install DVD. Before I go into the intended topic of this post, allow me to <rant> about how I’m not too keen on this decision. As a result, it’s no longer possible to install OSX on Macs that don’t have an internet connection (yes, these do exist!). Even for those who do, many don’t have very fast internet connections, or may have extremely low usage caps. I know that UK internet providers still offer entry-level packages 5Mbit lines and stupidly low 1-5 GB monthly limits. Lion is likely to be about 4GBs in size. Oh, you want to install OSX on more than one Mac? Suuure, just download the 4GB install package on each Mac.</rant> You get the point…

The real thing I wanted to talk about is Apple’s solution to system re-installation or recovery, and specifically the security implications thereof. Installing Lion will cause it to create a small ‘recovery’ partition on your primary drive, which is essentially a partition equivalent of an install DVD. If you have a problem with your main OSX partition, and need to run repair utilities or reinstall, you just boot from the recovery partition. Sounds really useful actually, as you don’t need to worry about having a DVD handy. But where this solution brings ease-of-use and convenience, it also brings some security risks.

Although Mac OS X is still largely unaffected by malware, the winds of change are indeed upon us, and it’s unrealistic to assume the Mac will remain virus-free forever. As viruses get more complex they find ever-improving ways of making themselves persistent on a system. There are countless examples of Master Boot Record viruses on Windows where the only sure-fire solution is to completely wipe the hard drive and reinstall from CD/DVD. Because once your system is infected, good security practice forces you to assume that any file or executable is compromised. So, how does this affect a bootable recovery partition? If I were a virus writer, I’d make pretty darn sure that I infect a core installer file on the recovery partition so that any  installation will have my virus. The nice thing about DVDs is that even if you insert them into an infected computer, they can’t be changed, and so you have complete confidence (barring a very advanced/rare firmware virus) that wiping and reinstalling from DVD yields a fresh and clean install of your system. As a security professional, I don’t think I’ll be able to trust a recovery partition like that.

But wait, there’s more. Viruses are a concern, but if you’re a smart user they’re not really a problem. We can run anti-virus, disable Flash, Java and Javascript, etc, and as long as you browse safely and don’t open random executables you’ll be perfectly fine. What about an attacker with remote or physical access to your computer? If I remotely hack into someone’s Mac, either due to a vulnerability or a weak password, all I have to do is modify a few files in the existing system and the recovery partition, and boom, persistent back door! The user can reinstall OSX all they want… my back door will simply be reinstalled with it.

But wait, there’s more. Even if your computer is completely secure from remote attacks, the same goes for someone with physical access to your Mac. Now, as a disclaimer, I have to point out that anytime an attacker gets physical access to any computer it’s game over. Even if you use FileVault, I may not be able to log in to your computer (unless some kind of cold boot attack is still possible), but I can easily boot your computer from a USB stick (or remove your hard drive if you have a Firmware password), trojan your recovery partition and corrupt your primary boot partition (similar to an Evil Maid attack). What are you going to do? Reinstall Mac OS X from my trojaned recovery partition of course! It’s not like you have a choice.

Any system compromise can lead to the installation of a persistent backdoor for the lifetime of the recovery partition on that hard drive. I don’t want to sound overly critical; I am probably one of the most fervent Apple supporters you’ll ever meet (with good reasons too), but not to the extent it stops me from thinking about potential impacts. I appreciate that Apple is trying to make things easier for Joe User. Being able to download updates electronically is awesome, and I honestly believe many would take advantage of that (myself included), but users should be given the choice. Particularly in situations like this where not having a physical install medium can have an impact on both usability and security.

My guess (or maybe hope) is that if Apple is not going to sell install DVDs itself, we may be allowed to burn our own install DVDs after downloading Lion from the Mac App Store. Either way, it is fairly trivial to burn the Lion installer onto a DVD – but users shouldn’t have to (or sometimes can’t) resort to a hack like that. Take heed, Apple.

[Update 21/07/11] Ok, so Apple isn’t going to allow users to burn their own DVDs, but they have confirmed that Lion will be available on a mini USB drive in August (for $69).


Understanding Apple’s Approach to Security

With Apple’s growing market share in desktop computers, and relative dominance in mobile computing, the security of Mac OS X and iOS are increasingly becoming talking points. Apple continues to tout the security of OSX, whilst the iOS hacker community keeps looking for (and finding) exploits that will allow them to jailbreak iPhones and iPads. This article is my own look into Apple’s history and strategy, and how this translates into the company’s focus on security today. Read moreRead more


Protecting and Recovering Your iPhone and iPad from Loss and Theft

My sister recently had her iPhone stolen, and it occurred to me that not enough people know how to help protect their iPhone/iPad from theft, what to do if it gets lost or stolen, and the steps to take even if they’re unable to get it back. Using a combination of security tips and geolocation, using Find My iPhone, you should have a much higher chance of recovering your device. Note that although this article is iPhone/iPad-centric… the principles apply to any smartphone!

NEW! Please refer to my Find My iPhone FAQ for the answers to some frequently asked questions (especially before asking a question in the comments). Read moreRead more


Insecurity: Bad Secret Questions and Information Disclosure

It’s a little known fact that most websites have a backdoor that can get you access in other people’s accounts – weak secret questions! Ok, so maybe it’s not a back door as such, but the threat is so high that for some websites it might as well be. Let me explain… Read moreRead more


The Power of Information: A Critique of Privacy, Wikileaks and Recent Events

The recent explosion of Wikileaks and Cablegate has yet again brought the unique power of information to the forefront of the world’s attention. What makes this different from the usual ‘knowledge is power’ debate, is that it highlights the sensitive balance between those wishing to reveal information to the world, and those who, for whatever reason, want to prevent that from happening. Historically it was the role of investigative journalists to look into the activities of companies and governments, however due to the high costs of long-term investigative stories, political affiliations, the chance of government gag orders, and the threat of lawsuits, these have been in decline. It is not only massive government-focused leaks that have been gagged in the past, smaller journalists and even individuals have been prevented from legally reporting or capturing an event. Read moreRead more