Defense

Windows Remote Management 101

Windows Remote Management is easy if you are using a domain joined machine and have a CA. But what if you are off the domain and you want to connect to WINRM that has an HTTPS listener? (by default WINRM uses HTTP on TCP 5985, you can clearly chop out the TLS related configs in the example scripts and they will work for plain old WINRM)

This is useful from a sysadmin and penetration testing/red team perspective. Now obviously you could export the certificates and import them into your store, however that’s more work. So, let’s look at how we ignore revocation, CA name and Computer Name checks.

Text Description automatically generated with medium confidence

WinRM via HTTPS (self-signed)

Read more “Windows Remote Management 101” →

Defense

Penetration Testing

Overview

Penetration testing is the activity of conducting security testing with the aim of identifying and exploiting vulnerabilities to identify strengths and weaknesses. I include strengths because I believe it’s important for security testing to promote both positive and negative findings. I also think that there is a huge mis conception with what penetration is, what it helps with and how to best get value from a penetration test.

My definition isn’t too far from the NCSC one: https://www.ncsc.gov.uk/information/check-penetration-testing

A penetration test is a security assurance activity, but it’s one of many activities that I recommend people conduct. This is however largely only adopted by the few, for many a penetration test is a compliance tick box, either from a regulatory or contractual requirement.

When looking at a system a penetration test is not usually the most efficient starting point, especially if it’s from a black box perspective. Read more “Penetration Testing” →

Leadership

There’s never any time – A mRr3b00t Adventure

Introduction

I’ve been working with technology and its security for a while, I have travelled to different parts of the world, I’ve worked with major organisations, and I’ve worked with a whole range of organisations both from strategic advisory and at the coal face perspective. Now over the last twenty years I thought about how much has changed… and honestly, I don’t think much has.

Technology innovation, miniaturisation and adoption rates are through the roof, but I still see massively similar patterns. I’m not going to try and quote statistics, but I think it’s a fair to say the threat landscape has changed somewhat (for the worse!)

Back in the 2000s era we had networks running Windows 2000 and Windows Server 2000/2003, we had clients with open services which could largely be accessed from anywhere on the network. We had host-based firewalls from third party vendors, but these were rarely implemented, MSBlaster and Windows XP changed this dynamic somewhat, to say things haven’t improved on one front would be a lie, however the level of crime and access to technology globally has changed massively. Read more “There’s never any time – A mRr3b00t Adventure” →

Defense

Why are ransomware attacks so devastating? – Part 1

Introduction

“Ransomware is a major issue!”

Hang on maybe we need to re-phrase that:

“Weak security postures are a major issue!”

or perhaps.. why not both!

I’ve been working with digital technology management for over 20 years, I started out when I was a kid (literally) fixing people’s PCs in their offices, removing malware, improving configurations, writing batch file menus, and playing games. As time has gone on technology has shrunk and continually become more and more of our everyday lives.

Back in 2003 I responded internally to MSBlaster, an SMB worm that had a devastating effect for the time, by today’s standards it was child play, however I remember saying “it’s a good job it didn’t delete everything whilst it was here.” (Or something very similar. Post NACHI/Blaster my friends and I were talking about how worse it could get. Fast forward in time and it’s much worse. Yet when I look at networks, they don’t look very different to how they did back in the 2000s.

Despite a multi-billion-dollar cyber security industry, it seems daily that organisations are succumbing to “cyber-attacks” which commonly include ransomware. Why are they successful and why are they so impactful? Well, let’s take a look! Read more “Why are ransomware attacks so devastating? – Part 1” →

Defense

Audit NTDS.DIT using DSINTERNALS

Ok this assumes you know how to get the NTDS.DIT and SYSTEM registry hive out from a domain controller, if you don’t go looking, we might have blogged a few ways to do that! Now then, firstly, let’s Install DSInternals. From PowerShell 5 onwards you can simply run:

Install-Module -Name DSInternals -Force

Text Description automatically generated

You will likely need to set your execution policy:

Set-ExecutionPolicy -ExecutionPolicy Unrestricted

Now to dump the hashes we use: Read more “Audit NTDS.DIT using DSINTERNALS” →

Defense

Hacking Guide – AESREPRoast and Kerberoasting

Kerberos Pre-Authentication Hash Retrieval and Cracking

We can enumerate active directory to find accounts that do not require pre-authentication. There’s a simple way of doing this using Rubeus:

.\Rubeus.exe asreproast /format:hashcat

We can see there is a vulnerable account that has Kerberos Pre-Authentication disabled.

This hash can be loaded into hashcat and possibly cracked (the hash in the screenshot is weak on purpose) Read more “Hacking Guide – AESREPRoast and Kerberoasting” →

Defense

Changing a security posture requires changing your own behaviours

I’m sure you will have had a marketing firm or some random sales person on Linkedin tell you that security should be simple and that their product will save you from all the ATPs and nation state hax0rs under the sun. However let’s get real, thats almost certainly not true and also security isnt simple or we’d all be out of jobs and everyon woulndn’t be getting owned all the time.

Getting real

Read more “Changing a security posture requires changing your own behaviours” →
Defense

Ransomware Defence: Part 2a – Persistence, Privilege Escalation and…

Recap

In Part 1 (Initial Access Defence and Checklist) we looked at ways of hardening your attack surface to defend against initial access. When it comes to ransomware there is a range of elements and variables in the kill chain that need to be successful for the outcomes to be achieved by the criminals. Here we are going to move further into the kill chain to look at further defences. Remember you need to have an “Assume Breach” mindset if you are going to be able to defend against ransomware, that being said, there is a hell of a lot of things you can do for 0 to low investment costs that provide a great ROI. Now some of this is going to be repeated guidance from part 1, that’s ok repetition is good (make sure you are covered from multiple perspectives). Ok let us get to it! Read more “Ransomware Defence: Part 2a – Persistence, Privilege Escalation and Lateral Movement” →

Copyright (c) Xservus Limited