blue tangle

  Quick blog entry on detections for the Ghostpack discovery/reconnaissance tool Seatbelt . This entry will focus on looking at command line parameters that can be caught even if the executable itself is renamed, if I have time we can delve into other event log artefacts another time. From the Seatbelt github repo: Seatbelt is a C# project that performs a number of security oriented host-survey "safety checks" relevant from both offensive and defensive security perspectives. So essentially what the tool does is retrieve local system information that might have security or safety implications. In terms of commands that can be tacked on to Seatbelt there are a literal ton of options. But what we are going to focus on here are the command groups, which break the many, many available commands down into categories, so we have: All, User, System, Slack, Chromium, Remote, Misc. The groups above are invoked like this, if you wanted to run all checks: Seatbelt.exe -group=all And so

  In part one of these blog entries on command line obfuscation in Windows ( which you can find here , if you haven't read it), we covered some real basic SPL for detecting the usage of double quotes to potentially circumvent SIEM detections. One of the things I forgot to mention then is that counting specific characters in fields has a lot of potential uses within Splunk searches if you are prepared to think outside the box a little. For instance let's say you were looking at Apache web logs and you were wanting to find instances of directory (or path) traversal, someone appending something like "../../../../../../../../../../../../etc/passwd%00" to a url to try to get at your valuable files, you could modify the SPL as follows:   index=apache sourcetype=access_combined | eval traversalCount=mvcount(split( uri,"."))-1 | where traversalCount >=4 | stats values(uri) BY traversalCount clientip status   This would give you any instances of uris containing

  If you want inspiration for a slidedeck on the history of ransomware look no further. Where I wanted to nail down specific dates I looked for when ransomware strains or incidents made the mainstream news and used that as my base timeline. The slides cover the first incident of data held for ransom that I could find (in 1981) through to Karakurt as what I see as the future of ransomware, touching on targeted ransomware attacks and the advent of Big Game Hunting in between. The talk is made to be delivered in about 25 - 30 minutes, though I was cutting it rather close with that timing. Feel free to use and alter this PowerPoint as you wish.  

The only thing I find more fascinating than digital anti-forensics, obfuscation and defence evasion is coming up with ways to thwart those techniques as they are employed by adversaries in the wild. This will be a few posts about ways to detect Windows command line obfuscation using Splunk, but I'm sure that the SPL I'm going to include here could be adapted to create detections for other SIEM tools like elastic or Sentinel with relative ease. Think of this as a chance to look up a magician's sleeve for a little peek at the concealed dove. Before we look at detections though we need to define the problem itself, what is command line obfuscation (or “DOSfuscation”) and why is it a problem for defenders? I would urge anyone who is interested in learning more about this topic in depth to check out Wietze Beukema’s excellent SANS DFIR talk:   If you are following along with ATT&CK I think this technique is best mapped to T1027, Obfuscated Files or Information. One of t

  I'll be presenting at BSides Dundee on August 6th, discussing the entire history of ransomware in only 25 minutes. I've learned a lot doing the research for the talk. So much of what we understand about the history of hacking seems to be the same somewhat random selection of events written up with mistakes and incorrect assumptions then copied and pasted across dozens and dozens of blogs, news articles and academic papers forever, without anyone revisiting the actual primary sources for the events from the time that they happened. What was the first webshell to be written? Who was the victim of the first DDoS? What was the first computer virus discovered in the wild? Look any of this up online and you'll either find wildly conflicting answers or no information at all, we are not good at documenting our own history. Anyway, that's my rant over, look forward to giving this talk and hope to see some of you in attendance!

I've purchased the domain bluetangle.dev and renamed this blog. I really like the imagery of a blue fishing net undergoing constant repair, thinking about the blue team and how hard we struggle to stop things slipping by us. In terms of content, I'll still be poking around at red team and hacker tools and thinking about detections and threat hunts as I go. Here is some DALL-E art to commemorate the change. Back to regular updates soon.

    Time for part 2 of a few blogposts on threat actors disabling Windows updates. We covered why in the last post along with how, this time around we will be mostly focusing on detections.   We aren't just detecting disabled Windows updates though, we're detecting the steps required to actually delete and remove installed updates. First we look at usage of the Windows native binary takeown , which enables an administrator to recover access to files that was previously denied.   In this case we are looking at takeown grabbing access of folders relating to Windows updates Our Splunk search looks like this:   index=winlogs EventCode=4688  Process_Command_Line IN ("*\Windows 10 install\*", "*\Windows10Upgrade\*")  New_Process_Name="*\\takeown. exe" | stats  min(_time) AS earliest max(_time) AS latest count(Process_Command_Line) AS Count values(Process_Command_Line) AS Process_Command_Line BY Creator_Process_Name Account_Name ComputerName  | c