Measuring Cyber Defence Success

What does “good” cyber security look like? Sure, we can run a maturity assessment and see what good indicators are and we can create a baseline of our current state to establish where we are and what gaps we have (honestly in real terms this isn’t something to consider you should be doing this!) but how do we measure success in cyber security? Is every success an invisible outcome? Because one question that often comes to mind here is, just because we don’t see something, does that mean everything is ok? In the fast-paced world of cyber security, measuring success isn’t as easy as you would think. I’ll give an example of this, let’s say we don’t monitor, we get breached, but the threat actor just performs crypto mining (let’s say this is on premises) and we never really notice in the grand scheme of the world that our energy consumption costs have increased, if we didn’t know this had occurred, we might think our security is good. Read more “Measuring Cyber Defence Success” →

Defense

How to restore AdminSDHolder Object Permissions using ADSIedit

Ok so the other day “we” as a community put out some guidance around post active directory compromise actions for when you can’t simply nuke the forest from orbit. Well, following on from that a friend asked about how to restore AdminSDHolder permissions? Read more “How to restore AdminSDHolder Object Permissions using ADSIedit” →

Defense

CAF Workbook

Undertsanding the current state of cyber capability maturity across an organisation is no simple feat. The team at NCSC have created a really good set of guidance with CAF. With all things there’s different ways on consuming, understanding and leveraging good practises.

I often find have XLS workbooks incredibly valuable when looking at indicators of good practise inside organisations. With this in mind, I started to put the GAF indicators into a workbook. This isn’t complete yet. It needs refactoring so it can be pivoted etc. It also needs some parts added for metadata capture and analysis.

I’m publishing this because sitting collecting virtual dust is probably the least valuable thing that can occur.

Hopefully this is helpful to people, even in it’s current half baked state. I’ll and complete this at some point!

Threat Intel

CVE-2021-38647 – Open Management Infrastructure (OMI) RCE – Linux…

Situation

Ok so the situation is as per usual a bit fluid, when this first dropped I was looking at this with a “azure” lense, however as time goes on it appears this likely also covers any Linux distro with the Azure/SCOM/OMS agents installed. This may change the profile of risk considerable, not only from a public facing attack surafce but highly likely from a lateral movement persspective. I’m going to keep updating this as more intel comes in. (sorry I’d be clearer if I had a clearer picture myself)

This week 4 vulnerabilities were disclosed which affect ~~Azure~~ virtual machines running the Open Management Infrastructure (OMI) agent (think PowerShell remoting). As above the scope seems to be slightly wider with regard to SCOM/AZURE and OMS/Sentinel etc. agents for Linux (I want to confirm all of this but for now it seems this is the position)

Essentially these vulnerabilities allow for both network-based remove code execution (RCE) and local privilege escalation (LPE).

There is evidence of exploitation in honeypots.
There is a public proof of concept available for the RCE.
The internet facing attack surface from a global perspective seems low based on the data in Shodan and Censys however I’m not convinced this is currently giving a clear picture.
- So, check your azure networks, Vms and firewalls would be a sensible idea

CTF

Installing Kali 2021.3

Hax fun with the Dragon distro

Ok today we are going to look at deploying Kali 2013.3. The install process for this is fairly standard and familiar from previous version but for those new to this world, it seems like a good place to start.

Install Procedure (Virtual Machine)

Boot from the ISO

Read more “Installing Kali 2021.3” →

Defense

Post Compromise Active Directory Checklist

Nuke it from orbit, it’s the only way to be sure!

Ok, in an ideal world you can re-deploy your entire environment from scratch, but back in the most people’s real world’s that’s not that simple. So, what do we do if we can’t nuke from orbit in a post compromise situation? Well, we need to clean up! This isn’t an exhaustive list, not a total guide. it’s a quick list to make you think about some key common areas and actions that might need to be taken! after all if someone got r00t, who knows what they did! (trust me, most orgs monitoring is a bit naff!)

Guides

What if not everyone is a cyber expert?

Developing a Cyber Roadmap

Ok so this topic comes up a fair bit, but organisations and their management are often looking to ensure they are doing the right thing (no really this is a common phrase I hear with organisations) with regard to cyber security. THe challenge I think quite a few people have is even understanding what that even means. Sure you have a firewall, and antivirus and you had a yearly peneration test of a site that isn’t even touching your corproate network. You thought you were fine, but you keep seeing organisations get ransomared in the news and the board keep asking “are we ok?” so this then leads to a common position of maybe buying more widgets or thinking, well we haven’t been “hacked” so we must be doing ok.

Defense

Vulnerability Management – Actually doing it!

Vulnerability Management, Assessments and Vulnerability scanning is sometimes treated a with distain in the Offensive security community, I personally don’t understand that. Vulnerability management is key to inputting into security strategy, architecture, and operations. It’s coupled heavily to many other processes such as:

Asset Management
Risk Management
Patch Management
Change & Release Management
Security Testing
Security Monitoring

Before we start deploying let’s think about some areas for consideration when performing vulnerability scans:

Scope
- Asset/Hosts
  - IP Ranges
  - Hostnames
- Connectivity
  - VPNs
  - LAN/WAN
- Device Types and Configuration
  - Domain
  - Workgroup
  - Appliance
  - ICS
  - Printers
  - Network Equipment
- Unauthenticated View
- Authenticated View
  - Auth Types
  - Protocols
- Scheduling
- Authority to execute
Impact
- Performance
- Availability
- Confidentiality
Objectives and Outcomes
Reporting
- Information Flow
- Report Storage and Confidentiality

CTF

Abusing AdminSDHolder to enable a Domain Backdoor

If we have high privilege access to a domain, we will likely want to establish persistence with high privilege access. One mechanism to do this is to assign ourselves permissions to the adminSDHolder object in active directory:

Here we have the default adminSDHolder permissions. We are going to add our user “low” in here with modify or full control permissions: Read more “Abusing AdminSDHolder to enable a Domain Backdoor” →

CTF

How to Identify Hashes

Some hashes are obvious but even then, it’s a good job to check. There are a few ways to check a hash outside of manual validation.

Using the Hashcat example list:

https://hashcat.net/wiki/doku.php?id=example_hashes

Using hash-identifier:

https://github.com/blackploit/hash-identifier

Using cyberchef Analyse hash:

https://gchq.github.io/CyberChef/#recipe=Analyse_hash()

Using hash-id:

https://github.com/psypanda/hashID

Using HashTag:

https://github.com/SmeegeSec/HashTag

As you can see there are range of tools available to you, and remember if you want to keep the hashes to yourself you can download Cyberchef and run it locally!