Stegseek - A proper Steghide cracker at last!

During CTF challenges, they sometimes hide data inside an image with Steghide. The common way to solve these is to use steghide with a located password or crack the password from a wordlist. Up until now, this has been EXTREMELY slow with common brute-force applications re-running Steghide with each and every password in the list - Around 500 attempts per second on faster systems. When attempting to do this with a larger password list such as RockYou which contains millions of entries, this speed was obviously an issue.

During some recent browsing, I found a tool that can not only crack these passwords TWENTY THOUSAND TIMES FASTER, but in some cases can actually locate data inside a password-protected Steghide image without actually knowing the original password by brute-forcing every possible way that Steghide uses to embed the image in the first place o_O

Link to the tool on Github: Stegseek

TryHackMe Certs

A kind fellow bought me a 30-day membership to Premium TryHackMe, so I decided to get some of their certificates whilst I was able to. 

I also got this one last Christmas, although whilst I'm sticking them all here, I might as well include this one too.

Wireshark - Filtering for a Port Knocking sequence

In a recent CTF, I was required to analyze a .pcapng file to find a Port Knocking sequence. I didn't know an easy way to do this, and Google only gave up some half useful answers, so after a bit of research, I decided to write this post in the hopes that someone may stumble upon it in the future :)

Filter: (tcp.flags.reset eq 1) && (tcp.flags.ack eq 1)

Before

After

Make sure that the order number is correct (The "No." column goes from lowest to highest), and read the Port number on the left in the "Info" column.

In this case, the sequence is 7864, 8273, 9241, 12007, 60753, so a:

> knock 10.10.35.61 7864 8273 9241 12007 60753 -t 500

Would get you what you need. 

I found that sometimes you might need to knock 2 or 3 times before the filtered port opens for some reason, but there you go!

Photogenic Cheetah

 :D

What looks like binary, but isn't?

Whilst doing a CTF, I came across a crypto challenge similar to the following that looked like binary:

11111111110010001010101110101111111010111111111101101101101100000110100100101111111111111100101001011110010100000000000010100110111100101001001011111111111001010011111111111111100101001011100101000101011110010100000000000000000000000000010101110010100111110010100110010100101111100101001010010100110111111111111111111111111111100101001111111111111111111111110010100100100000000000000000000000000000000000000000000000000000000000000000000000010100100000000000000000000000000000000000000000000010100010101111111001010000000000001010111111111111111001010

After it failed decoding AS binary, I tried the Magic option on CyberChef which failed, and several variations of the Baconian cipher - Which also failed.

After much searching and many failings, I came across Spoon - An esoteric programming language whose code looks like binary. A quick Google search led me to this online interpreter from dCode. Pasting in the text and clicking the "Execute" button got me the result I needed!

The one honest VPN video on YouTube

Exploiting Webmin 1.890 through cURL

In a recent CTF, I came across a legacy version of Webmin with a Metasploit module. I prefer to do things without Metasploit, so decided to use cURL.

In the above, you can see that Webmin is running by the page title - "Login to Webmin" and the version - "Server: MiniServ/1.890"

This specific version of Webmin has a backdoor with an associated Metasploit Module. The exploit looked easy enough, so I decided to do it manually.

Basic code execution.

We're already root...

And there's the flag. I won't cat it in this post, but there you go.

Diagnosing a weird lack of RAM

Whilst recently playing Warframe, the game crashed with an "Out of Memory" error. I found this to be a bit odd as I have 32GB RAM.

Checking Task Manager, I saw my RAM Usage was weirdly high (25GB / 31.9GB). After closing everything (Chrome, Discord, Visual Studio, SQL Server, etc), it was still sitting at 19GB which was still really high.

I downloaded the latest version of RAMMap to figure out what was going on. It didn't show any process leaking anything (I have had issues with excessive Modified Page List Bytes being used in the past since I intentionally have no Pagefile - But it wasn't the case here). Then I saw something odd.

The "Nonpaged Pool" (Whatever that was?) was using up 13.1GB RAM. I didn't realize that was unusual until I searched around and figured out that it should be taking around 500MB - Max - On a Server - With over 100 days uptime. Something was definitely up!

After extensive research, I found out that the "Nonpaged Pool" was a collection of RAM used up by System drivers. Most people simply recommended to reboot when it gets high, but that wasn't good enough for me - I wanted to figure out what was wrong!

I eventually came across this awesome page which got me to install the latest Windows SDK to get a process called "poolmon.exe" (Installing a 9GB SDK for a single app seems excessive, but I couldn't figure out any other way to get it...). After running the program and ordering things, the issue was immediately apparent.

Something with the tag of "AfdB" was using up 6821892960 Bytes (Or 6.8GB) of RAM, whilst the next highest thing "EtwB" was using up 33046784 Bytes (or 33MB) of RAM.

I opened up CMD and ran

> findstr /m /l /s AfdB C:\Windows\System32\Drivers\*.sys

And came up with two results.

> C:\Windows\System32\Drivers\afd.sys

> C:\Windows\System32\Drivers\EasyAntiCheat.sys

So, the problem was either in afd.sys (The "Ancillary Function Driver for WinSock"), or EasyAntiCheat.sys (A third-party anti-hacking program installed by some games). You can most likely guess which one was the issue :p

The EastAntiCheat.sys in my System32\Drivers folder was from 2016. The latest version correctly located at C:\Program Files (x86)\EasyAntiCheat\EasyAntiCheat.sys was from 2019. I rebooted in Safe Mode, deleted the one in System32, and rebooted again.

After 3 days of uptime, my PC is now sitting at a happy 5GB / 31.9GB, and the Non-paged pool is at a much happier 148MB. Much better :)

Running openvpn without it hanging the terminal

Whilst messing around with HackTheBox, I attempted to connect to the VPN from an Ubuntu VM I have with Google.

The annoying part was that after it ran, it would hang at "Initialization Sequence Completed", and required a second terminal connection to continue. If I Control+C'd, it would kill the VPN connection.

After a bit of searching, I found that I could run it then background it by going

> sudo openvpn Reelix.ovpn &

In which case it would still hang at "Initialization Sequence Completed", but I could Control+C it without it killing it. Close... But the hanging annoyed me.

After a bit more searching, I found that OpenVPN had a --daemon parameter, but going

> sudo openvpn Reelix.ovpn --daemon

Threw up an error

> Options error: I'm trying to parse "Reelix.ovpn" as an --option parameter but I don't see a leading '--'
> Use --help for more information.

After much searching, I eventually discovered the trick!

> sudo openvpn --config Reelix.ovpn --daemon

Success!

To kill the connection, I could either go

> sudo pkill -f "openvpn --config Reelix.ovpn"

Or

> ps aux | grep openvpn
> sudo kill -2 processIdHere

Starcraft 2 AI Battles!

Whilst going through my daily news, I found an article about how an AI Bot in Starcraft 2 managed to beat the hardest native SC2 AI. In my search for the videos of these battles (Which I couldn't find), I managed to find the SC2 API for bots, and with a little more searching - The SC2 AI Ladder.

Browsing their Wiki, I came across a SC2 Bot writted in C#. So, I did what any awesome developer would do - I downloaded it, customized the daylights out of it, and entered it into the AI Ladder (Without expecting to actually get anywhere - Only a few hours work after all). After a few problems with uploading (Which the Site Admin helped me out with on Discord!), I managed to get a working bot onto their ladder.

The initial results amazed me!

Not only was my bot not absolutely terrible - It was winning almost every match it entered! In fact, it had a 78% Win Rate (And a 22% Crash Rate which was destroying my rating...) - And that was just the first version!!! I fixed some crashes, optimized some code, fiddled with the gameplay, and re-entered my Bot - Eager to see how the new changes affected the ratings!