Embrace The Red

Playing around with Bing Chat is quite fun. Until today I mostly used ChatGPT and GPT-4 directly, but I was curious of the capabilites and restrictions of Bing Chat. I noticed that as soon as I mentioned the word “hacker”, Bing Chat became quite “uncomfortable”. For instance, when I asked it to imagine being a hacker and list some security vulnerabilities, it replied: I’m sorry but I cannot help you with that.

Once in a while I go build some fun new tools to adopt new tech. Just last week OpenAI made their gpt-3.5-turbo model accessible via API endpoints. Update: The latest version also supports GPT-4. So, I thought it’s time to start building a tool to leverage it. What is yolo? Do you know those moments when you can’t remember a shell command, or some arguments to it? How do you pipe all errors to /dev/null again?

Recently I got the feedback to create more tutorials and videos, and I thought SSH Agent Hijacking on Linux and macOS (which I wrote about before here) would make a good one. The video tutorial is here. If you like this kind of content, then comment or like the video on YouTube and I’ll create more. Hope it’s useful to get a good basic understanding of this TTP, and help build detections for it.

There is a combination of lesser known tools and techniques to capture and later decrypt SSL/TLS network traffic on Windows. This technique is neat because it does not require the installation of additional driver/software when capturing the traffic. Technique, Tools and Steps It is quite straight forward and consists of: Setting the SSLKEYLOGFILE environment variable to capture TLS session keys on target host Use netsh trace start to capture traffic (no need to install additional driver/software!

After reading this post about ChatGPT imitating Linux, I wanted it to be a database server. Let’s try it out! Imagine you are a Microsoft SQL Server. I type commands, and you reply with the result, and no other information or descriptions. Just the result. Start with exec xp_cmdshell ‘whoami’; Wow, this looks like a promising start. And, it “thinks” that it is running as LOCAL SYSTEM - quite funny actually.

As more organizations move to hardware tokens and password-less auth (e.g. Yubi-keys, Windows Hello for Business,…) attackers will look for other ways to to trick users to gain access to their data. One novel phishing technique is by using the OAuth2 Device Authorization Grant. This post describes how it works with Microsoft AAD as example. Attacker initiates the phishing flow The attacker starts a Device Code flow by issuing a request to the device code token endpoint (e.

Misconfigurations with MFA setups are not uncommon when using AAD, especially when federated setups or Pass Through Authentication is configured I have seen MFA bypass opportunities in multiple production tenants. A common misconfiguration is that MFA is enforced at the federated identity provider, but AAD is forgotten and ROPC authentication still succeeds against AAD. To learn more about ROPC, check out the previous post about the topic. This post focuses on the ropci features that can be leveraged post-exploitation.

Great news! An article about ropci is in the latest free issue of the Pentest Magazine! The article has a lot more info then my ropci blog post or the info on the ropci Github repo. Get your copy and check it out! It also has an article about Nuclei, one of my favorite tools. Cheers. Link: https://pentestmag.com/product/pentest-open-source-pentesting-toolkit

This post will highlight a pattern I have seen across multiple production Microsoft Azure Active Directory tenants which led to MFA bypasses using ROPC. The key take-away: Always enforce MFA! Sounds easy, but there are often misconfigurations and unexpected exceptions. So, test your own AAD tenant for ROPC based MFA bypass opportunities. Github: https://github.com/wunderwuzzi23/ropci Update: The latest free issue of Pentest Magazine has a ropci article. Check it out. What is ROPC?

There are some neat TTPs that I don’t use frequently, and if the time arises, I need to dig up details again. So, I figured to write some of them down, starting with SSH Agent Hijacking. What is SSH Agent Hijacking? Short story, if you have keys added to an SSH Agent an adversary with root permissions can use them. If you forward the SSH Agent to another host, an adversary with root permission on that other host can exploit and leverage your keys as well.

On a network and need credentials? Try password spraying the domain controller directly. A few years ago, I wrote this password spray tool called gospray that was used succesfully in a couple of engagements since. It does an LDAP bind directly against the domain controller to validate credentials. This doesn’t require an SMB server (or other servers) as target. So, it’s pretty quiet and number of concurrent Go routines is configurable.

This week I learned about a design flaw with pip download, which allows an adversary to run arbitrary code. I assumed that running pip install means anything could happen, but pip download seems a bit surprising. Both seem useful for red teaming though. Background This post from Yehuda Gelb named Automatic Execution of Code Upon Package Download on Python Package Manager which the Security Now! podcast pointed me towards. The post highlights that just running pip download can compromise your computer.

Recently I read this excellent post by Evan Sultanik about exploiting pickle files on Trail of Bits. There was also a DefCon30 talk about backdooring pickle files by ColdwaterQ. This got me curious to try out backdooring a pickle file myself. Pickle files - the surprises Surprisingly Python pickle files are compiled programs running in a VM called the Pickle Machine (PM). Opcodes control the flow, and when there are opcodes there is often fun to be had.

This post is part of a series about Offensive BPF. Click the “ebpf” tag to see all related posts. It has been a while that we posted something in the “Offensive BPF” series. But recently there have been a couple of new cool ebpf based tools, such as TripleCross, boopkit and pamspy. So, I thought it be quite fitting to do another post in the Offensive BPF series to keep raising awareness.

Pluggable Authentication Modules (PAM) on Unix based systems are useful to change logon behavior and enforce authentication via various means. In “Red Team Strategies” the chapter “Protecting the Pentester” walks the reader through the configuration of a PAM module to get notified in real-time via a pop-up when someone logs on to the machine (e.g. system compromise). But there are also bad things that can be done with PAM (especially post-exploitation) and this is what this post is about.

As the saying goes, a picture is worth a thousand words. In order to improve your documentation and uplevel red team and pentest reporting, it’s useful to add date and time information to screenshots and script logs. This helps the Blue Team (and yourself) reviewing past activity, reports and when deconflicting activity is required. Depending on the shell that is used there are different ways to go about it. Let’s cover three common ones.

In this post, we’ll examine how GPT-3 could be used by red teams or adversaries to perform successful phishing attacks. We’ll also discuss some potential countermeasures that organizations can take to protect themselves against this type of threat. What is GPT-3? GPT-3 is a neural network-based machine learning system that was developed by OpenAI, a research lab focused on artificial intelligence. It is designed to generate text that sounds realistic and human-like, and it has been trained on a large corpus of text, including billions of words from the internet.

Information for red teaming macOS and info on real world TTPs are still a bit sparse. That makes it difficult for defenders to know what attackers do on macOS compared to Windows. Some organizations might have a bigger blind spot when it comes to macOS. This post describes how an adversary can grab hashes from a macOS machine, how to convert it to a hashcat friendly format and use hashcat to crack it.

After a bit of a delay my Flipper Zero finally arrived in the mail. If you are not familiar with Flipper Zero at all, check out the original Kickstarter page from a few years back. This is what the package looks like after opening. It contains the device, a USB cable, a quick start manual (mostly pointing you to the Flipper Zero website), and a Flipper “Hack the planet” sticker.

One area that I have encountered quite often over the years is that during recon phase of a bug bounty hunt or pentest a set of AWS access keys are being discovered. Let’s say you found 50 AWS access keys by drooling and hunting through public Github repos and using other nifty tricks and means. How do you go about checking their validity? And what do they have access to and provide the Bug Bounty Program or Blue Team the dates, times, and IP address when those keys were used?