The title of this diary is perhaps a bit catchy but the question is important. I don’t consider myself as a good developer. That’s not my day job and I’m writing code to improve my daily tasks. I like to say “I’m writing sh*ty code! It works for me, no warranty that it will for for you”. Today, most of my code (the skeleton of the program) is generated by AI, probably like most of you.

[This is a Guest Diary by Matthew Presnal, an ISC intern as part of the SANS.edu BACS program]

Introduction

Today, Microsoft released patches for 113 vulnerabilities. One of these vulnerabilities affected the Edge browser and was patched upstream by Chromium.

Reverse engineers must have a good understanding of the environment where malware are executed (read: the operating system). In a previous diary, I talked about malicious code that could be executed when loading a DLL[1]. Today, I’ll show you how a malware can hide suspicious information related to created processes.

I'm always looking for new ways of manipulating the data captured by my DShield sensor [1]. This time I used Gephi [2] and Graphiz [3] a popular and powerful tool for visualizing and exploring relationships between nodes, to examine the relationship between the source IP, filename and which sensor got a copy of the file. I queried the past 30 days of data stored in my ELK [4] database in Kibana using ES|QL [5][6] to query and export the data and import the result into Gephi. 

In yesterday's podcast, I mentioned "tailsnitch", a new tool to audit Tailscale configurations. Tailscale is an easy-to-use overlay to Wireguard. It is probably best compared to STUN servers in VoIP in that it allows devices behind NAT to connect directly to each other. Tailscale just helps negotiate the setup, and once the connection is established, data will flow directly between the connected devices. I personally use it to provide remote assistance to family members, and it has worked great for this purpose. Tailscale uses a "Freemium" model. For my use case, I do not need to pay, but if you have multiple users or a large number of devices, you may need to pay a monthly fee. There are also a few features that are only available to paid accounts.

Recently, a new "breed" of IP-based KVM devices has been released. In the past, IP-based KVM devices required dedicated "server-grade" hardware using IPMI. They often cost several $100 per server, and are only available for specific systems that support the respective add-on cards. These cards are usually used to provide "Lights Out" access to servers, allowing a complete reboot and interaction with the pre-boot environment via simple web-based tools. In some cases, these IPMI tools can also be used via various enterprise/data center management tools.

One of my holiday projects was to redo and optimize part of my home network. One of my homelab servers failed in November. I had only thrown the replacement in the rack to get going, but some cleanup was needed. In addition, a lot of other "layer 1" issues had to be fixed by re-crimping some network drops and doing general network hygiene. The dust buny kind hygiene, not so much the critical controls type. After all, I don't want things to overheat, and it is nice to see all network links syncing properly.

Xavier's diary entry "Abusing DLLs EntryPoint for the Fun" inspired me to do some tests with TLS Callbacks and DLLs.