Tag: AI

Enhancing Malware Analysis with REMnux and AI

DFIR, Forensics, Malware, REMnux

Those familiar with my work know that I’m a big fan of the REMnux Linux distribution for malware analysis. When I developed MalChela, I included a custom configuration that can be invoked that not only includes the MalChela tool suite but also integrates many of the CLI tools installed in REMnux, providing an easy-to-use GUI.

Recently, a new REMnux release was released on Ubuntu 24.04. This was a welcome upgrade because REMnux was previously locked to 20.04, which was becoming outdated. As soon as I noticed the release announcement, I downloaded the latest version and installed the MalChela suite. Everything ran smoothly, and the GUI interface even appeared slightly sharper without any changes on my part.

While reviewing the release notes for the new version, I discovered that REMnux now includes integration with Opencode AI. In REMnux, several models are preconfigured to recognize the tools included in the distribution and their capabilities and syntax. You can use natural language prompts, and the system will interpret the request, execute the appropriate tools against the file, and provide a summary of the results. As mentioned in the documentation:

The AI uses the REMnux MCP server to run the appropriate REMnux tools automatically. The MCP server offers guidance regarding the tools that the AI should consider, but it’s up to the AI agent to decide on the analysis workflow. And, of course, your interactions, requests, and observations can also direct the AI regarding the analysis steps.

Key capabilities available to AI assistants through the REMnux MCP server:

  • Analyze files based on detected type (PE, PDF, Office docs, scripts, ELF, etc.)
  • Get tool recommendations for a specific file without running them
  • Run specific REMnux tools directly, including piped commands
  • Extract indicators of compromise (IOCs) from text
  • Get usage help for any installed REMnux tool

I experimented with a few of the usual suspects in my corpus and provided pretty generic prompts like “analyze (file-xyz)” and “what are the IOCs?” The results were very positive – but I’ve only scratched the surface in testing.

Then I decided to see how adaptive this AI was and how easy it would be to make it aware of new tools and syntax. I provided the following:


MalChela tool suite is  installed in /home/remnux/Tools/MalChela
All are rust based tools so cd to the MalChela directory, and then ./target/release/fileanalyzer (path to executable) would be the syntax. 
The 4 tools below are the primary tools for static analysis.
  File Analyzer       |  Get the hash, entropy, packing, PE info, YARA and VT match status for a file  
  mStrings            |  Analyzes files with Sigma rules (YAML), extracts strings, matches ReGex. 
  NSRL Hash Lookup    |  Query an MD5 or SHA1 hash against NSRL
  Malware Hash Lookup |  Query a hash value against VirusTotal & Malware Bazaar 

Immediately it began running the tools in MalChela against the malware file I was previously analyzing and provided a summary of the different tool results.

I plan to do a lot more testing but so far things are looking very promising.

So what do you think? Are you using AI in your malware analysis workflows? What capabilities of AI do you think are most useful when it comes to malware analysis? Let me know in the comments.

Huntress CTF: Week 3 – Miscellaneous: Who Is Real?, Operation Eradication

CTF, DFIR, Miscellaneous

Who Is Real?

This was a change of pace from what a lot of the CTF has been; lots of malware and deobfuscation. In this challenge we’re tasked with figuring out which faces are real and which have been AI generated.

Before starting the challenge, I familiarized myself with

https://whichfaceisreal.com/learn.html

It gave me good ideas of things to look for regarding teeth, glasses, earrings, other faces in photos, etc.

Eventually, I was able to get 5 right in a row.

Operation Eradication

Let’s take a look at the configuration file.

This looks like a config file for rclone.

Using this information, and the url provided from the challenge, we can update our rclone config file.

Now using rclone we can connect to the remote location and hopefully start deleting these ‘sensitive’ files. If only it were so easy.

I was able to get a directory listing, so I knew that my credentials were successfully connecting.

I was all over the command options at https://rclone.org. Every DELETE or SYNC operation I could think of was failing.

At my wit’s end I pinged a friend who suggested trying to overwrite the files with a 0 bit file. If successful the files would still be there, but the content gone – so essentially, they’d be safe again.

Using the file listing from the server, I wrote a PowerShell script that would touch, or create a 0 byte file, locally for each file names.

Next the script would run the rclone copy command to copy the local 0 byte files to the network location.

I run the PowerShell script and then return to the webpage and refresh…

DOH! There was a typo in one line of the script. I’ll re-run the file listing command again. All but one file have the 0 byte file size.

Run the copy command one more time to take care of our errant file and…

Success!

Use the tag #HuntressCTF on BakerStreetForensics.com to see all related posts and solutions for the 2023 Huntress CTF.