Jorrit Folmer jorritfolmer

0. Prep container host

This HOWTO assumes Red Hat Enterprise Linux 9.x or 10.x with Podman. Even though this is a lab, the assumptions are that the skeleton could be scaled to something in production without major reconstructions, hence the reason for the elaborate TLS incantations that could easily be replaced by requesting certificates to be signed by another Root CA.

Download containers

How to add memtest86+ to the UEFI grub2 boot menu in Red Hat Enterprise Linux 9

The two methods below can be used to boot Memtest86+ from the grub2 boot loader on Red Hat Enterprise Linux 9. This is convenient when a system is located in a datacenter instead of on your desk, and has a remote console like e.g. iLO. Unfortunately the most recent Memtest86+ v7 cannot currently detect correctable ECC errors, so the only hint is very low performance in the memtest interface like the elapsed timer not updating every second. In that case EDAC errors filling up /var/log/messages are a more reliable indicator.

Using the EFI filesystem and a /etc/grub.d config file

Download the Binary Files (.bin/.efi) from https://www.memtest.org
Create a new directory /boot/efi/EFI/tools/

Generic syslog building block

The rsyslog config below realises a reusable building block to onboard syslog data, for example into Splunk. It assumes an on-prem enterprise environment and uses the file system as a buffer/queue to decouple syslog senders from a receiver like Splunk Universal Forwarder (UF). This way you can restart Splunk UF without any data loss.

The following four configuration files ensure:

Reception of syslog into one log file for every source IP address.
Fitness for a high volume syslog setup by having rsyslog NOT throttle
Least privilege for Splunk UF by having rsyslog create files with appropriate umask and group
Retention of all log files for 1 day to prevent availability issues from "disk full" scenarios

Securonix RIN installation

Prerequisites

You need at least 8 GB of RAM for the installation to succeed. If not, the installer will give you weird errors. See below for the difference in output between a successful and unsuccessful installation.

Replace a1redacted-abcd` with your own tenant name and code.

Preparation

Mounting Defender for Endpoint Telemetry data on Linux

Defender Telemetry data can be persisted in Azure Blob Storage. This results in datetimestamped directories containing JSON files.

Why?

So you can easily Splunk, gzip or jq some of your telemetry data

How?

Offline Windows lab from scratch

Windows 2019 domain controller
Windows 10 Pro domain joined workstation
Creating Microsoft Office offline DVD image
Installing ISO on Windows 10 Pro

1. Installing a Windows 2019 domain controller

This is a condensed version of https://petri.com/how-to-install-active-directory-in-windows-server-2019-using-powershell

MITRE EDR evaluations round 3

For easier Splunking use the steps and Python script below.

Download MITRE EDR json files

wget https://attackevals.mitre-engenuity.org/downloadable_JSON/AhnLab_Results.json
wget https://attackevals.mitre-engenuity.org/downloadable_JSON/Bitdefender_Results.json
wget https://attackevals.mitre-engenuity.org/downloadable_JSON/CheckPoint_Results.json

How to use Tailwind CSS with Pelican

These steps show how to install Tailwind CSS in a Pelican project, purge and minify it so you don't have to reference a 3+ MB CSS file but only several kB.

virtualenv venv
. venv/bin/activate
pip install nodeenv
nodeenv env
. env/bin/activate
npm install postcss postcss-cli autoprefixer tailwindcss purgecss cssnano

AWS Route53 DNS logging via CloudWatch Logs

^\S+ \d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d+Z \S+ (?<query>\S+) (?<record_type>\S+) (?<reply_code>\S+) (?<transport>\w+) (?<dest>\S+) (?<src>\S+) (?<vendor_edns_client_subnet>\S+)

	<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
	<plist version="1.0">
	<dict>
	<key>Label</key>
	<string>com.example.tmpwatch</string>
	<key>ProgramArguments</key>
	<array>
	<string>/opt/homebrew/sbin/tmpwatch</string>
	<string>--mtime</string>