Month: March 2020

vysolator: vyos virtual network isolation

Sometimes projects are just born out of pure frustration, this is one of those projects. I’ve probably build like a dozen VyOS configurations to virtually isolate networks and virtual machines on my host. I  briefly touched upon this subject a couple of years ago when I wrote about stashing ESXi inside VMware workstation to achive a portable lab. Since then I’ve build multiple versions, to either ensure that Red Team operations and regular penetration tests are able to contain the breach to a single virtual machine or to enable training networks with multiple networks and clients. If we visualize a simple setup it looks like this:

This compartmentalizes potential breaches to their own segment. In this case each segment has a single VM, but it could contain multiple VMs. Yes, the virtualization layer becomes a single point of failure. I still think it adds value from most attacks that you could suffer. Including the usual surfing the internet and getting pwned one.

So here is a repo which contains the instructions and example config file to get you (read: most probably future me) started. The current setup ensures that you have one mgmt segment and one internet only segment. That means, you can manage your VyOS from the mgmt segment if you place a VM in it. You can browse the internet and nothing else if you place a VM in the internet only segment.

Whenever I build more segments that lend themselves to be of generic use I’ll update the repo. Feel free to send pull requests with either alternative configurations or improvements and segment expansion on the current one. @donnymaasland, already had a sneak preview and submitted some improvements. You can view the historical commits to review the improvements as well as some personal preferences on rules.

On and yes, I do agree that Qubes OS is a superior solution, however this is more versatile. Also this does not have the same threat model that Qubes OS has. For those wondering about the threat model for this, here is a quick summary of it / the intended features:

      • Contain regular breaches to a single segment
      • Protect against regular attacks
      • Not intended to withstand targeted or advanced attacks
      • Avoid user mistakes by enforcing network ACLs from a central system
        • Improve ease of use by just requiring users to place VMs in the right segment
      • Aid Red Team / Pentest to not fuckup when they have to use specific exit IP addresses

Lessons learned on written social engineering attacks

I’ve had some interesting conversations on the topic of performing social engineering attacks via email and decided to share some of my past lessons learned. The focus will not be so much on the technical side as it will be much more focused on the social aspect. Although much of today’s written social engineering attacks are carried out using email, there are other written communication methods which can and should be used depending on your objectives.

The social aspect for me concerns the journey from the moment the victim receives the email until the moment that your objective is achieved. Whereby the objective often relates to infecting the victim it could also involve having the victim send you some documents or perform other actions. The victim’s social journey is something that can be influenced, but in my experience it is not something that you’ll fully control.

When I started out with attacking organizations and individuals I was often under the impression that everything should work on the first try. This of course is not true. What is true, is that you should assume failure and put some thought and effort into the consequences. One of the more important lessons I learned early on in regards to performing social engineering via written media is:

It really doesn’t matter, nobody cares.

Have you ever looked at your own communication? have you ever worked in a SOC or followed up on incidents? Eventually most companies as well as victims are pretty tired of the endless stream of shit that they receive on a daily basis. So yes, there will be investigations, they might even follow-up on your attack, but then what? It’s not like they can block all senders or block the entire internet or forbid their employees from working and talking to potential customers, partners, vendors right? So yeah, you guessed it right, if you mess up:

You get to try it again, and again and again…

Of course there are some exceptions like when you really mess up and they figure out you’ve been hired to attack them or if you technically have a ‘tell’ which would enable them to block all incoming attacks pretty quickly. Although…how would they block you across all possible communication channels that their employees use?

Anyhow I’m getting ahead of myself, let’s talk about some war stories and I hope you learn as much as I did from them. As usual I garbled up a lot of information, timelines and other details to attempt some anonymization. Oh and yes, the technical part of these attacks eventually matters, specially if you have to get some code execution, but with the proper social engineering context this can sometimes become much, much easier to perform.

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