At Elastic Security Labs, together with Eric Forte and Samir Bousseaden, we analyzed the Linux kernel privilege escalation vulnerabilities Copy Fail (CVE-2026-31431), Copy Fail 2, and DirtyFrag. These issues exploit subtle page cache corruption bugs to create reliable paths to root access, using legitimate kernel …

In the second part of our two-part Linux rootkit series at Elastic Security Labs, Remco Sprooten and I turn from theory to detection engineering. We begin by demonstrating why static detection is often unreliable against Linux rootkits—even trivial modifications like stripping binaries or appending a single null byte …

At Elastic Security Labs, Remco Sprooten and I analyzed a data dump containing source code, compiled binaries, and deployment scripts for the kernel rootkit components of VoidLink—a cloud-native Linux malware framework first documented by Check Point Research. The dump revealed a multigenerational rootkit framework …

At Elastic Security Labs, I published a real-world walkthrough of TeamPCP's multi-stage container compromise, demonstrating how Elastic's Defend for Containers (D4C) surfaces runtime signals across each stage of the attack chain. Rather than analyzing isolated techniques in abstraction, we follow the attack as it …

At Elastic Security Labs, I published a comprehensive walkthrough of Elastic's Defend for Containers (D4C) integration, covering Kubernetes-based deployment, BPF-enriched runtime telemetry analysis, and the practical application of policy-driven security controls for containerized Linux environments. Defend for …

In the first part of our two-part Linux rootkit series at Elastic Security Labs, Remco Sprooten and I explore the theory behind how rootkits work: their taxonomy, evolution, and the hooking techniques they use to subvert the kernel. We trace the progression from early userland shared object rootkits through LKM-based …

At Elastic Security Labs, Remco Sprooten and I analyzed OUTLAW, a persistent yet unsophisticated auto-propagating coinminer package that remains active across multiple versions despite lacking advanced evasion techniques. It leverages simple but impactful tactics such as SSH brute-forcing, SSH key and cron-based …

In the fifth and final part of the Linux Persistence Detection Engineering series, we bring the journey to its grand finale by exploring some of the most obscure, creative, and complex persistence mechanisms. Building on the foundational concepts covered in previous publications, this final installment focuses on …

In the fourth part of the Linux Persistence Detection Engineering series, I continue exploring advanced Linux persistence techniques, expanding on the foundation set in previous publications. This latest installment delves into additional creative and complex methods adversaries use to maintain persistence on Linux …

In the third part of the Linux Persistence Detection Engineering series, I continue exploring advanced Linux persistence techniques, expanding on the foundation set in previous publications. This latest installment dives into more creative and complex persistence methods, providing security researchers and defenders …

At Elastic Security Labs, we uncovered PUMAKIT, a sophisticated multi-stage Linux malware with advanced rootkit capabilities. Initially identified through routine threat hunting on VirusTotal, PUMAKIT consists of a dropper (cron), two memory-resident executables, an LKM rootkit module, and a userland shared object (SO) …

At Elastic, we recognize the critical need for securing containerized applications in Kubernetes and cloud environments. To enhance runtime security, we’ve integrated Falco—an open-source cloud-native security tool—directly with Elastic Security. Falco leverages Linux kernel events and plugins to detect abnormal …

At Elastic Security Labs, we analyzed a critical set of vulnerabilities in the CUPS printing system, disclosed by security researcher Simone Margaritelli (@evilsocket) on September 26, 2024. These flaws, affecting CUPS versions ≤ 2.0.1, enable unauthenticated remote attackers to achieve remote code execution (RCE) via …

At Elastic Security Labs, we uncovered a sophisticated Linux malware campaign exploiting Apache2 servers since March 2024. Attackers used multiple malware families, including KAIJI (DDoS) and RUDEDEVIL (crypto miner), along with custom tools for persistence and control. They leveraged C2 channels disguised as kernel …

In this second part of the Linux Persistence Detection Engineering series, I explore the world of more advanced Linux persistence techniques. This part builds upon the knowledge obtained from the previous persistence blog dubbed "Linux Detection Engineering - A Primer on Persistence Mechanisms". This sequel …

In this first installment of the Linux Persistence Detection Engineering series, I delve into Linux persistence mechanisms, exploring both common and complex techniques to enhance the knowledge of defenders and security researchers. I examine how these persistence methods operate, how to set them up, and most …

In this article, I explore how to effectively use Auditd and Auditd Manager for detection engineering. I’ll demonstrate Auditd's powerful features, guide you through the setup process, and show you how to create and modify rules to capture specific behaviors. You'll also learn how to interpret the logs and discover how …

This research delves into large-scale malware analysis conducted by Elastic Security Labs, highlighting how Elastic ingest pipelines were used to filter out benign and duplicate data during dynamic malware analysis. By leveraging these pipelines, we efficiently managed vast datasets, enabling us to focus on identifying …

Welcome back! Today we are going to solve the Timelapse machine from Hack The Box. Timelapse is an easy box which focuses on accesible SMB shares and a lot of hash cracking to get the initial foothold. We then find configuration files that allow us to login to the system as the administrator user. Foothold Let's start …

Today we will be taking a look at the medium box "Undetected" from Hack The Box. The foothold for the box can be found through a vulnerable php script in a directory that should not be world accessible. The script allows for remote code execution onto the box as the www-data user. We then escalate to user by …

This blog post will cover server-side request forgery (SSRF) attacks. Along the way we will be covering what a SSRF is, take a look at the basics of a SSRF attack, discuss several more advanced SSRF attacks and learn about the ways to prevent your web application of being vulnerable to these types of attacks. While …

Welcome to my Hack The Box walkthrough for the "Meta" box. The box is considered to be of medium difficulty. Meta requires you to perform DNS virtual host enumeration, identify the inner workings of an image upload functionality, and exploit this to get a foothold. We then find a vulnerable version of …

Today we will be taking a look at Timing from Hack the Box. Timing is considered to be of medium difficulty, and requires the usage of a local file inclusion to eventually find credentials for the box. We then find an application that we can run with sudo permissions, and misuse it to gain root access. Foothold Let's …

In this post we will be taking a look at the directory traversal or path traversal vulnerability. I'll go over what directory traversal exactly is, how we can weaponize it, how we can bypass common protections and misconfigurations and lastly how to prevent it within your own web application. While elaborating on this …

In the fourth post regarding web application security, we will be diving into OS command injection or shell injection attacks. We will be covering what command injection is, what different types of command injection attacks exist and how to prevent command injection vulnerabilities within your own web applications. …

This post will explain what SQL-injection (SQLi) is, how we can find SQLi vulnerabilities in web applications, how we can weaponize this vulnerability and how to prevent it. While researching and explaining the topic, we will go through several easy and more advanced examples that are available for free at PortSwigger …

Hello everyone, today we are going to take a look at Unicode from Hack The Box. Unicode is a medium box that involves JWT manipulation, local file inclusion and a custom made application that can be used to access the root flag. Foothold As usual, we start off with an nmap scan to enumerate all ports, services and …

This tutorial is part two of a two part series that focuses on binary exploitation, in particular on x86 stack-based Windows buffer overflows. The first part of the series focuses on the theory behind the topics that will be described in this tutorial, and can be found here. The information provided in this blog is …

This tutorial is part one of a two part series that focuses on binary exploitation, in particular on x86 stack-based Windows buffer overflows. This part of the series focuses on the theory behind memory, processors and buffer overflows. We first take a look at some simple c programs and assembly, then dive into the …

Today we will be taking a look at "Shibboleth" from Hack the Box. To get get a foothold onto the box we first exploit the vulnerable-by-design IPMI protocol to obtain an administrator hash for Zabbix, and crack it. Through Zabbix we can execute local commands and obtain a shell. We can then use a recent …

Welcome to my walkthrough for the "Backdoor" machine from Hack The Box. Backdoor is considered to be an easy box. We get a foothold onto the box through the exploitation of a vulnerable web service running at an unusual port. We can then escalate privileges through a screen session that was still open, which …

This post is based on the notes and cheatsheets I wrote while studying for the Offensive Security Certified Professional (OSCP) exam, and can be used as a brief reference while looking for basic Windows privilege escalation methods. The contents of this blog originate from the “Windows Privilege Escalation for OSCP …

This post is based on the notes and cheatsheets I wrote while studying for the Offensive Security Certified Professional (OSCP) exam, and can be used as a brief reference while looking for basic Linux privilege escalation methods. The contents of this blog originate from the "Linux Privilege Escalation for OSCP …