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”

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

The grass is always greener, until it is not

A PwnDefend Story – Day 7

It is a blur so far, I figured after the last place the grass would be greener, surely no one else has that many security challenges. I did some due diligence during the interview process, they seemed very confident about having certifications and that they took security seriously. hell, that should have set some red flags off but even the cynical sometimes hope that it is as someone says.

I have started to work myself around the board and I am making friends with people, my diary is filled with zoom calls and my notebook is already many pages deep.

You cannot make this stuff up though, day two and I’ve dealing with a business email compromise incident, the phishing page was not even in good English but then it only takes a second or so whilst in a meeting to not quite realise your running on autopilot so you cannot blame people. Hell, the branding was copied so we know it was a targeted phish. It would have been nice to at least had centralised logs for the team to analyse though. Read more “The grass is always greener, until it is not”

Defense

Field Notes – Just Patch

Windows update stuck at 0% download status

Often is we find an environment missing software updates it’s easy for someone without hands on experience to say, ‘just patch’. Outside of change requests, outside of authorisation, maintenance windows, roll back plans, communications etc. there is also the fact that ‘just patching’ isn’t that simple. Even for fairly standard patching tasks using Windows Updates you sometimes hit a snag. Today I’m looking at exactly that issue on a server, so I thought I’d post the steps to resolve an issue but also, I think this is a nice way to highlight the realities of patching.

We show a GUI and command line (PowerShell) method to achieve this result (the PowerShell isn’t fancy but I figured you could go away and upgrade that if you fancied some fun). Windows update sometimes has issues (does not all software!) and it is sometimes that we need to help it along the way, so let’s get too it! Read more “Field Notes – Just Patch”

Breach

Extortion and Ransomware – A lethal Combination

A Brief History of Ransomware

Ransomware is not that new, I remember back during the msblaster incident I said to a friend, it is a good job whoever wrote this worm was not evil because they would have simply encrypted or deleted all the data post infection. Hell, I can barely remember when that was, I think it was late 2003. Ransomware has been around since the 1980s but not quite in its modern form (it started with the AIDS malware scam). Fast forward to the mid 2000’s and criminals were using encryption but that wasn’t a norm and things only really started to take a bad turn around 2012/2013 with Cryptolocker. The next major global events were WannaCry, NotPetya and Badrabbit. Read more “Extortion and Ransomware – A lethal Combination”

Defense

Vulnerability Management Realities

Trust but verify

Someone tells you they have fixed something, now go and check! You might find that it is not actually fixed, or that the ‘fix’ made the issue worse (or makes new vulnerabilities appear). You might however also find that the vuln is gone.

Wow so many options, but the reality is with this space is that you have to keep checking, you also need to validate.

Validation is key, people do not say that think it is fixed because they have not done something, we all have scenarios where we make a change, assume it works and then find out later that maybe a bit more testing would have helped (I have this too!). Read more “Vulnerability Management Realities”

Defense

Everything must be agile but is that really always…

A lot of people talk about AGILE but the normally mean ‘agile’ however when it comes to security testing and penetration testing (to me there is most certainly a difference) we need to be mindful of the different approaches, so we select the right one for the context, scenario, and objectives.

In this post we take a brief look at what we recommend for a range of scenarios and we look at the key differences and what some constraints might mean when it comes to approach selection.

Read more “Everything must be agile but is that really always the best way?”