TheHive - an excellent case management tool for Digital Forensics!

 In my work in cybersecurity, I've been quietly using TheHive made by Strange Bee https://strangebee.com/thehive/ for the last few years. Initially I was searching for something to analyse forensic data and stumbled on this project. It's got both an Open Source and a paid version, and I've had great value from the community version. Paired with Cortex, TheHive is a powerful tool for the cybersecurity professional. Cortex is the system that does the analysis of your artefacts and then reports back into TheHive. This isn't the only integration that TheHive supports. You can push new cases into it from both MISP and from Wazuh, and then run triage and analysis from within TheHive. It will push details back into MISP so when you review an alert or report, then you can classify it in TheHive once, and it will update it back into MISP which is pretty neat.

Here is what a couple of entries on the Dashboard looks like:

The dialogue box to create a case is below 

And this is what the case page looks like:

Typically, I'll do the following:

• Create a case, choosing the appropriate level of severity
• Add at least one task to the case - usually "Review Observables" which is TheHive talk for artefacts associated with the case - and these can be all different types
• Add the observables - of which there can be many types as seen in this screenshot: 
  
  
  
  and with the "Type" sorted out:
  
  
  
  Here is where TheHive and Cortex shine together. The observable type is linked to analytics that Cortex runs for you - you'll have to set it up, but the good news is, it's quite straightforward and can all run on a single server. Cortex will run the analysis of your observable and then report back. For example, you might configure Cortex to query Google DNS for bad websites, VirusTotal for known bad artefacts, AbuseFinder is handy, and so is Urlscan.io. Here is an example of what a couple of bad IP addresses look like after Cortex has analysed them:
  
  Red is bad, Orange is suspected bad and green is... well Cortex either isn't sure or the results are inconclusive. 

Cortex requires some grunt to run, so when you read that TheHive + Cortex needs 16GB of RAM and at least 8 CPUs you can understand why - with many concurrent analytics being performed against the observables, and doing it in a timely manner. I run it on my Proxmox server and it gets along quite adequately. 

When you're working through the case, I use the Tasks to capture what I'm seeing, and use the "Comments" to report on my findings. These can be timestamped (which you should always do) and if you happen across an observable or a similarity to another case, TheHive will automatically link it through. Then you can begin the next phase of action, whatever that may be, and track the case to its finale. In the example above, we saw significant attacks on our Web Application Firewall and blocked the addresses, fixing the problem from a known bad (at the time) IP address. It may have been fixed since, and that's why it is important to re-analyse observables. Hijacked sites/IPs or similar can be recovered and I always want to give my fellow cyber security and IT pros the chance to fix their systems without needlessly blocking anyone. 

TheHive has nice reporting (I don't have an example that doesn't have sensitive data in it), and I've found as a system for managing what I am seeing and being asked to respond to, it has been excellent. I use the Community edition - I don't get a lot of cases through work, but I do get a few when I'm helping out people outside of the office and TheHive is great for supporting that community work. I've had several interactions with their team and they've been generally very good, so thank you StrangeBee members!

I've meant to write about TheHive for a while - it's a great tool, and I think that if you've got a forensic element to your work it can really add value to that work. 

Digital forensics on an SSD

Recently I was able to listen to a guest lecturer by a chap working the digital forensics field. There were a few interesting things to come out of the lecture. They are, in no particular order:

• document and timestamp everything you do - it doesn't matter if it's written down, or you use software, but you have to show the steps you went through to reach the conclusions you're putting forward
• EnCase is an industry favourite software
• small cases can take you in surprising directions and you can go from a $40,000 fraud case and end up with a $250,000 + fraud case!
• recovering RAID arrays can be a trick - but you can image each disk and use EnCase to rebuild the array which is pretty neat!
• you can't carve an SSD to recover data like you would a HDD

That last point is the one I want to mention. On a magnetic hard disk drive (the regular type of drive people have been using) when a file is deleted, it's removed from the File Allocation Table and the computer recognises it as free space, ready to overwrite. It's relatively straightforward to then get that data back - a process I've performed dozens of times to save someone's bacon when they've deleted all their uni work (for example). But on an SSD the process is different. 

On a TRIM enabled SSD (and this is all modern SSD's) the data is removed immediately when you delete it. The OS clears the space for re-use and it's not recoverable. This applies to USB drives as well - any flash media in fact. Once a file is marked for deletion, the operating system erases it completely and then that space is available again. This keeps the SSD running fast. It makes it very hard, if not impossible to perform data carving (or recovery) on an SSD. Uh oh - that makes life harder for the digital forensic expert! 

It's amazing though - even with these kinds of hurdles to getting data out and processing it, people still make it easy to be caught. For example, using work email to talk about things people are doing wrong, or storing data on work computers that has evidence of wrong doing. There is no expectation of privacy when you use a work asset - the company owns all this stuff and all the data on it. And most companies will comply with search orders giving an investigator plenty of access to what they are looking for.

It's interesting stuff, but I don't think I'll make a career of it - getting into the business seems quite tricky and while it is a fascinating field, there is a lot of tedious combing through search hits for relevant results that, quite frankly, looks boring. Never say never though!

More on Digital Forensics

So the SIFT workstation is up and running - almost. My slow internet connection is making the updating take a long time. Yesterday it ran almost all day to get SIFT on the machine. Lots of changes from stock Ubuntu - app installs, timezone changes, and the theme has been tarted up.

I looked at the digital images yesterday and thought about how to go about all of this. It's a little bit more complex than I thought. I know what I want, and I know what the output should be, its the pesky bits in the middle that are causing me some annoyance. Specifically the steganography output and how to carve the text files to get into what is clearly inside them. They are far too large for the text that they have.

I understand the methodology - it's quite clearly outlined in the text book, but there's a big difference between having your head around that and applying it. In order to write the report I have step through things fairly systematically - it's the way the old brain works and getting that system into some sort of operational semblance is the trick. There are some great cheatsheets on the desktop of a new SIFT install, for which I'm profoundly grateful. I'll read through these and have a good think.

There is a lot of info about forensic work out there. The glut of it makes it time consuming to go through, yet enjoyable at the same time. Once I've had a bit more time, I'll make known some of the posts that I've found interesting and relate my own experiences here!