Tag: malware_analysis

This is part 2 of my writeup for the Maldoc101 challenge. Check out part 1 for the beginning of the analysis.

The next couple of lines does the same concatenating technique similar to the previous steps.

deaknaugthein = roubhaol.kaizseah.ControlTipText
giakfeiw = deulsaocthuul + gooykadheoj + roubhaol.paerwagyouqumeid.ControlTipText + deaknaugthein
queegthaen = giakfeiw + roubhaol.joefwoefcheaw

At the end of the code above queegthaen now contains the value Win32_Process + s + tar + tu + P. Or when combined creates the string Win32_ProcessstartuP which probably refers to this WMI class in the Microsoft docs.

Note: This writeup appears to be incomplete. For the complete analysis, please refer to part 1 of this series.

This is part 1 out of 2 of my writeup for the Maldoc101 challenge made by Josh Stroschein (@jstrosch) and is currently playable at Cyberdefenders.Org. I've done some maldoc analysis before but this is the first time I'm writing about my approach.

There is also an already existing writeup about this challenge from the creator himself. You should check that out if you want a more detailed and focused writeup. This writeup is more from the perspective of someone relatively new to malware analysis. There's a lot more exploration and trial-and-error which, I hope, might give the reader a different view in how this kind of problem is approached.

The challenge

Name

MalDoc101 - Malicious Document

Description

It is common for threat actors to utilize living off the land (LOTL) techniques, such as the execution of PowerShell to further their attacks and transition from macro code. This challenge is intended …

[Edit: shcode2exe is now part of Remnux]

I've been playing around with Remnux and encountered a problem trying to get one of the tools to run properly. The tool is shellcode2exe, it is used to compile binary shellcode to a file so it can easily be debugged by a debugger.

When I checked out the code, I was surprised to find out how simple it is. Basically, what happens is that the inputted shellcode is added to a barebones assembly file using the incbin assembly instruction. From there, the file is then automatically compiled and linked.

One big problem with the tool is that it needs to use Wine if it needs to run on Linux. I don't want such a huge dependency especially for my own malware analysis lab so I decided to write my own version which have led to the creation of shcode2exe.

shcode2exe

While similar in …

I joined the Defcon Red Team Village CTF because I was curious about it and I wanted to test out the skills that I have gained playing with CTF sites like overthewire.org and vulnhub. I knew that the challenges won't be easy, but thankfully, I was able to join up with other newbies who were willing to give it a go and learn with each other.

Unfortunately, I fell asleep just before the CTF started and when I woke up all the easy challenges were already solved by my team members. There was one easy challenge that was still open on the CovidScammers category, so I quickly got started to solving that.

Free Flag (and binary) [1 point]

You've been contacted by a high-end but morally ambiguous finance company (unhackable-bitcoin-wallet.com) to investigate a data breach. The box in question is a mail server in their internal network, a …