Blog.Bajiri

  VeeBeeeee: A Microsoft Script Forensics Challenge VeeBeeeee starts with an extensionless file. When attempting to open this file, we get a bunch of random junk. I used PowerShell to display the content of the file and then dropped the output into CyberChef to decode it. Using the “Magic” function on CyberChef told me that it was a Microsoft Script, and CyberChef applied the Microsoft Script Decoder function to the text blob. Copy/Pasting the cleartext code into VSCode lets us use the find and replace function to get rid of some of this junk data. While going through the script and getting rid of the tacked-on strings and characters, we can see that there is an array being built called Request. If we follow the link in this array, we get to a Pastebin file with the flag.   Fetch: A Prefetch and WIM File Analysis Challenge Fetch provided an unknown file with no extension. Like previous challenges, we can use the “file” command to determine the file type. Using ...

  Snake Eater: A Malware Analysis Challenge Snake Eater provided an executable file with the comment “I’ve never seen an executable file that looks like this. Can you check it out and see what it’s doing”. The comment is the hint to finding the flag. This challenge requires a Virtual Machine, as the executable is based on live malware and Defender may delete it or prevent it from running. First, we’ll need to get our hands on Sysinternals tools. These can be downloaded from Microsoft. After getting all of the Sysinternals tools, we need to go back to our hint. The line “Can you check it out and see what it’s doing” is a hint that we need to run the malware and see what changes it’s enacting on the system. One way to do this is to use Process Monitor from Sysinternals. We can run the Process Monitor executable and start capturing with no filters enabled. Then, we can execute the snake_eater.exe file and wait for it to close. After it closes, we can stop the Process Monitor c...

HumanTwo: MoveIT IoC Analysis Challenge The HumanTwo challenge is a malware CTF from the 2023 Huntress CTF. This write-up walks through the initial discovery, de-obfuscation, and solving of the challenge. The actual flag will be redacted from the document, but interested parties should be able to follow the steps and derive it themselves. While the write-up assumes a base level of knowledge regarding the command line and Linux. Most tools and commands will be accompanied by short explanations. Step 1: Initial Analysis To start off, we are given an archive with 1000 files named after their file hash. The hint we are given is that there are minor differences between each file. We also know that HumanTwo relates to the MoveIT vulnerability and exploit. The easy way to progress is to look up articles that tell you about the vulnerability and what stands out in each exploit script. However, I didn’t do that, so I’ll put the process I followed down instead. First, because I knew that...

I'm finally getting around to uploading these. My team and I had a blast doing the Huntress CTF and we learned quite a bit doing them! Formatting might be weird on some of these. They're copy/pastes from word docs. Hot off the Press: A PowerShell Malware Challenge Hot off the Press is a malware CTF challenge from the 2023 Huntress CTF. This write-up walks through the initial discovery, de-obfuscation, and solving of the challenge. The actual flag will be redacted from the document, but interested parties should be able to follow the steps and derive it themselves. While the write-up assumes a base level of knowledge regarding the command line, Linux, cryptography, and PowerShell. Most tools and commands will be accompanied by short explanations. This is a fun entry-level malware reversal challenge that is completable by all entry-level cybersecurity students with a little research. Step 1: File Discovery The file “hot_off_the_press” was given with the explanation that thi...